MCP4728 Data Sheet

MCP4728
12-Bit, Quad Digital-to-Analog Converter with EEPROM Memory
Features
Description
• 12-Bit Voltage Output DAC with Four Buffered
Outputs
• On-Board Nonvolatile Memory (EEPROM) for
DAC Codes and I2C™ Address Bits
• Internal or External Voltage Reference Selection
• Output Voltage Range:
- Using Internal VREF (2.048V):
The MCP4728 device is a quad, 12-bit voltage output
Digital-to-Analog Convertor (DAC) with nonvolatile
memory (EEPROM). Its on-board precision output
amplifier allows it to achieve rail-to-rail analog output
swing.
0.000V to 2.048V with Gain Setting = 1
0.000V to 4.096V with Gain Setting = 2
- Using External VREF (VDD):
0.000V to VDD
• ±0.2 Least Significant Bit (LSB) Differential
Nonlinearity (DNL) (typical)
• Fast Settling Time: 6 µs (typical)
• Normal or Power-Down Mode
• Low Power Consumption
• Single-Supply Operation: 2.7V to 5.5V
• I2C Interface:
- Address bits: User Programmable to
EEPROM
- Standard (100 kbps), Fast (400 kbps) and
High Speed (HS) Mode (3.4 Mbps)
• 10-Lead MSOP Package
• Extended Temperature Range: -40°C to +125°C
Applications
•
•
•
•
•
•
•
•
•
Set Point or Offset Adjustment
Sensor Calibration
Closed-Loop Servo Control
Low Power Portable Instrumentation
PC Peripherals
Programmable Voltage and Current Source
Industrial Process Control
Instrumentation
Bias Voltage Adjustment for Power Amplifiers
© 2010 Microchip Technology Inc.
The DAC input codes, device configuration bits, and
I2C address bits are programmable to the nonvolatile
memory (EEPROM) by using I2C serial interface
commands. The nonvolatile memory feature enables
the DAC device to hold the DAC input codes during
power-off time, allowing the DAC outputs to be
available immediately after power-up with the saved
settings. This feature is very useful when the DAC
device is used as a supporting device for other devices
in the application’s network.
The MCP4728 device has a high precision internal
voltage reference (VREF = 2.048V). The user can select
the internal reference or external reference (VDD) for
each channel individually.
Each channel can be operated in Normal mode or
Power-Down mode individually by setting the
configuration register bits. In Power-Down mode, most
of the internal circuits in the powered down channel are
turned off for power savings, and the output amplifier
can be configured to present a known low, medium, or
high resistance output load.
The MCP4728 device includes a Power-on Reset
(POR) circuit to ensure reliable power-up and an
on-board charge pump for the EEPROM programming
voltage.
The MCP4728 has a two-wire I2C compatible serial
interface for standard (100 kHz), fast (400 kHz), or high
speed (3.4 MHz) mode.
The MCP4728 DAC is an ideal device for applications
requiring design simplicity with high precision, and for
applications requiring the DAC device settings to be
saved during power-off time.
The MCP4728 device is available in a 10-lead MSOP
package and operates from a single 2.7V to 5.5V
supply voltage.
DS22187E-page 1
MCP4728
Package Type
MCP4728
MSOP
VDD 1
10 VSS
SCL 2
9 VOUT D
SDA 3
8 VOUT C
LDAC 4
7 VOUT B
RDY/BSY 5
6 VOUT A
Functional Block Diagram
LDAC
EEPROM A
VDD
INPUT
REGISTER A
VSS
SDA
SCL
I2C Interface Logic
EEPROM B
INPUT
REGISTER B
EEPROM C
INPUT
REGISTER C
EEPROM D
RDY/BSY
INPUT
REGISTER D
Internal VREF
(2.048V)
OUTPUT
REGISTER A
UDAC
OUTPUT
REGISTER B
UDAC
OUTPUT
REGISTER C
UDAC
OUTPUT
REGISTER D
VREF Selector
VDD
DS22187E-page 2
UDAC
VREF A
STRING DAC A
VREF B
OP
AMP B
VOUT B
Power Down
Control
Output
Logic
OP
AMP C
VOUT C
Power Down
Control
Gain
Control
STRING DAC D
VOUT A
Power Down
Control
Output
Logic
Gain
Control
STRING DAC C
VREF D
OP
AMP A
Gain
Control
STRING DAC B
VREF C
Output
Logic
Gain
Control
OP
AMP D
VREF
Output
Logic
VOUT D
Power Down
Control
(VREF A, VREF B, VREF C, VREF D)
© 2010 Microchip Technology Inc.
MCP4728
1.0
ELECTRICAL
CHARACTERISTICS
† Notice: Stresses above those listed under “Maximum
Absolute Maximum Ratings†
VDD...................................................................................6.5V
All inputs and outputs w.r.t VSS ................. -0.3V to VDD+0.3V
Current at Input Pins ....................................................±2 mA
ratings” may cause permanent damage to the device. This is
a stress rating only and functional operation of the device at
these or any other conditions above those indicated in the
operation listings of this specification is not implied. Exposure
to maximum rating conditions for extended periods may affect
device reliability.
Current at Supply Pins ............................................. ±110 mA
Current at Output Pins ...............................................±25 mA
Storage Temperature ...................................-65°C to +150°C
Ambient Temp. with Power Applied .............-55°C to +125°C
ESD protection on all pins ................ ≥ 4 kV HBM, ≥ 400V MM
Maximum Junction Temperature (TJ) ......................... +150°C
ELECTRICAL CHARACTERISTICS
Electrical Specifications: Unless otherwise indicated, all parameters apply at VDD = +2.7V to 5.5V, VSS = 0V,
RL = 5 kΩ, CL = 100 pF, GX = 1, TA = -40°C to +125°C. Typical values are at +25°C, VIH = VDD, VIL = VSS.
Parameter
Symbol
Min
VDD
2.7
IDD_EXT
—
Typical
Max
Units
Conditions
5.5
V
800
1400
µA
VREF = VDD, VDD = 5.5V
All 4 channels are in Normal mode.
—
600
—
µA
3 channels are in Normal mode,
1 channel is powered down.
—
400
—
µA
2 channels are in Normal mode,
2 channel are powered down.
—
200
—
µA
1 channel is in Normal mode,
3 channels are powered down.
Power Requirements
Operating Voltage
Supply Current with
External Reference
(VREF = VDD)
(Note 1)
Power-Down Current with
External Reference
IPD_EXT
—
40
—
nA
All 4 channels are powered down.
(VREF = VDD)
Supply Current with
Internal Reference
(VREF = Internal)
(Note 1)
IDD_INT
—
800
1400
µA
VREF = Internal Reference
VDD = 5.5V
All 4 channels are in normal mode.
—
600
—
µA
3 channels are in Normal mode,
1 channel is powered down.
—
400
—
µA
2 channels are in Normal mode,
2 channels are powered down.
—
200
—
µA
1 channel is in Normal mode,
3 channels are powered down.
—
45
60
µA
All 4 channels are powered down.
VREF = Internal Reference
Power-Down Current with
Internal Reference
Note 1:
2:
3:
4:
5:
6:
7:
8:
9:
IPD_INT
All digital input pins (SDA, SCL, LDAC) are tied to “High”, Output pins are unloaded, code = 0 x 000.
The power-up ramp rate measures the rise of VDD over time.
This parameter is ensured by design and not 100% tested.
This parameter is ensured by characterization and not 100% tested.
Test code range: 100 - 4000 codes, VREF = VDD, VDD = 5.5V.
Time delay to settle to a new reference when switching from external to internal reference or vice versa.
This parameter is indirectly tested by Offset and Gain error testing.
Within 1/2 LSB of the final value when code changes from 1/4 of to 3/4 of full scale.
This time delay is measured from the falling edge of ACK pulse in I2C command to the beginning of VOUT.
This time delay is not included in the output settling time specification.
© 2010 Microchip Technology Inc.
DS22187E-page 3
MCP4728
ELECTRICAL CHARACTERISTICS (CONTINUED)
Electrical Specifications: Unless otherwise indicated, all parameters apply at VDD = +2.7V to 5.5V, VSS = 0V,
RL = 5 kΩ, CL = 100 pF, GX = 1, TA = -40°C to +125°C. Typical values are at +25°C, VIH = VDD, VIL = VSS.
Parameter
Symbol
Min
Typical
Max
Units
Conditions
Power-on Reset
Threshold Voltage
VPOR
—
2.2
—
V
All circuits, including EEPROM, are
ready to operate.
Power-Up Ramp Rate
VRAMP
1
—
—
V/s
Note 2, Note 4
n
12
—
—
Bits
Code Change: 000h to FFFh
Integral Nonlinearity (INL)
Error
INL
—
±2
±13
LSB
Note 5
DNL Error
DNL
-0.75
±0.2
±0.75
LSB
Note 5
VOS
—
5
20
mV
Code = 000h
See Figure 2-24
DC Accuracy
Resolution
Offset Error
Offset Error Drift
Gain Error
Gain Error Drift
ΔVOS/°C
—
±0.16
—
ppm/°C -45°C to +25°C
—
±0.44
—
ppm/°C +25°C to +125°C
GE
-1.25
0.4
+1.25
% of
FSR
ΔGE/°C
—
-3
—
ppm/°C
2.048
2.089
Code = FFFh,
Offset error is not included.
Typical value is at room
temperature
See Figure 2-25
Internal Voltage Reference (VREF), (Note 3)
Internal Voltage Reference
Temperature Coefficient
VREF
ΔVREF/°C
2.007
V
—
125
—
ppm/°C -40 to 0°C
—
0.25
—
LSB/°C
—
45
—
ppm/°C 0 to +125°C
—
0.09
—
LSB/°C
Reference Output Noise
ENREF
—
290
—
µVp-p
Code = FFFh,
0.1 – 10 Hz, Gx = 1
Output Noise Density
eNREF
—
1.2
—
μV HZ
Code = FFFh, 1 kHz, Gx = 1
1/f Corner Frequency
fCORNER
Note 1:
2:
3:
4:
5:
6:
7:
8:
9:
—
1.0
—
—
400
—
Code = FFFh, 10 kHz, Gx = 1
Hz
All digital input pins (SDA, SCL, LDAC) are tied to “High”, Output pins are unloaded, code = 0 x 000.
The power-up ramp rate measures the rise of VDD over time.
This parameter is ensured by design and not 100% tested.
This parameter is ensured by characterization and not 100% tested.
Test code range: 100 - 4000 codes, VREF = VDD, VDD = 5.5V.
Time delay to settle to a new reference when switching from external to internal reference or vice versa.
This parameter is indirectly tested by Offset and Gain error testing.
Within 1/2 LSB of the final value when code changes from 1/4 of to 3/4 of full scale.
This time delay is measured from the falling edge of ACK pulse in I2C command to the beginning of VOUT.
This time delay is not included in the output settling time specification.
DS22187E-page 4
© 2010 Microchip Technology Inc.
MCP4728
ELECTRICAL CHARACTERISTICS (CONTINUED)
Electrical Specifications: Unless otherwise indicated, all parameters apply at VDD = +2.7V to 5.5V, VSS = 0V,
RL = 5 kΩ, CL = 100 pF, GX = 1, TA = -40°C to +125°C. Typical values are at +25°C, VIH = VDD, VIL = VSS.
Parameter
Symbol
Min
Typical
Max
Units
Conditions
Analog Output (Output Amplifier)
Output Voltage Swing
VOUT
—
FSR
—
V
Note 7
Full Scale Range
(Note 7)
FSR
—
VDD
—
V
VREF = VDD
FSR = from 0.0V to VDD
—
VREF
—
V
VREF = Internal, Gx = 1,
FSR = from 0.0 V to VREF
—
2 * VREF
—
V
VREF = Internal, Gx = 2,
FSR = from 0.0V to 2 * VREF
TSETTLING
—
6
—
µs
Note 8
Analog Output Time Delay
from Power-Down Mode
TdExPD
—
4.5
—
µs
VDD = 5V,
Note 4, Note 9
Time delay to settle to new
reference
(Note 4, Note 6)
TdREF
—
26
—
µs
From External to Internal
Reference
—
44
—
µs
From Internal to External
Reference
Power Supply Rejection
PSRR
—
-57
—
dB
Capacitive Load Stability
CL
—
—
1000
Slew Rate
SR
—
0.55
—
Phase Margin
pM
—
66
—
Short Circuit Current
ISC
—
15
24
mA
Short Circuit Current
Duration
TSC_DUR
—
Infinite
—
hours
Output Voltage
Settling Time
DC Output Impedance
(Note 4)
Note 1:
2:
3:
4:
5:
6:
7:
8:
9:
ROUT
pF
VDD = 5V ±10%, VREF = Internal
RL = 5 kΩ
No oscillation, Note 4
V/µs
Degree CL = 400 pF, RL = ∞
(°)
VDD = 5V,
All VOUT Pins = Grounded.
Tested at room temperature.
Note 4
—
1
—
Ω
Normal mode
—
1
—
kΩ
Power-Down mode 1
(PD1:PD0 = 0:1), VOUT to VSS
—
100
—
kΩ
Power-Down mode 2
(PD1:PD0 = 1:0), VOUT to VSS
—
500
—
kΩ
Power-Down mode 3
(PD1:PD0 = 1:1), VOUT to VSS
All digital input pins (SDA, SCL, LDAC) are tied to “High”, Output pins are unloaded, code = 0 x 000.
The power-up ramp rate measures the rise of VDD over time.
This parameter is ensured by design and not 100% tested.
This parameter is ensured by characterization and not 100% tested.
Test code range: 100 - 4000 codes, VREF = VDD, VDD = 5.5V.
Time delay to settle to a new reference when switching from external to internal reference or vice versa.
This parameter is indirectly tested by Offset and Gain error testing.
Within 1/2 LSB of the final value when code changes from 1/4 of to 3/4 of full scale.
This time delay is measured from the falling edge of ACK pulse in I2C command to the beginning of VOUT.
This time delay is not included in the output settling time specification.
© 2010 Microchip Technology Inc.
DS22187E-page 5
MCP4728
ELECTRICAL CHARACTERISTICS (CONTINUED)
Electrical Specifications: Unless otherwise indicated, all parameters apply at VDD = +2.7V to 5.5V, VSS = 0V,
RL = 5 kΩ, CL = 100 pF, GX = 1, TA = -40°C to +125°C. Typical values are at +25°C, VIH = VDD, VIL = VSS.
Parameter
Symbol
Min
Typical
Max
Units
—
45
—
nV-s
Conditions
Dynamic Performance (Note 4)
Major Code Transition
Glitch
Digital Feedthrough
—
<10
—
nV-s
Analog Crosstalk
—
<10
—
nV-s
DAC-to-DAC Crosstalk
—
<10
—
nV-s
1 LSB code change around major
carry (from 7FFh to 800h)
Digital Interface
Output Low Voltage
VOL
—
—
0.4
V
IOL = 3 mA
SDA and RDY/BSY pins
Schmitt Trigger
Low Input
Threshold Voltage
VIL
—
—
0.3VDD
V
VDD > 2.7V.
SDA, SCL, LDAC pins
—
—
0.2VDD
V
VDD ≤ 2.7V.
SDA, SCL, LDAC pins
Schmitt Trigger
High Input
Threshold Voltage
VIH
0.7VDD
—
—
V
SDA, SCL, LDAC pins
Input Leakage
ILI
—
—
±1
µA
SCL = SDA = LDAC = VDD,
SCL = SDA = LDAC = VSS
CPIN
—
—
3
pF
Note 4
Pin Capacitance
EEPROM
EEPROM Write Time
TWRITE
Data Retention
—
25
50
ms
—
200
—
Years
210
—
—
ns
EEPROM write time
At +25°C, Note 3
LDAC Input
LDAC Low Time
Note 1:
2:
3:
4:
5:
6:
7:
8:
9:
TLDAC
Updates analog outputs (Note 3)
All digital input pins (SDA, SCL, LDAC) are tied to “High”, Output pins are unloaded, code = 0 x 000.
The power-up ramp rate measures the rise of VDD over time.
This parameter is ensured by design and not 100% tested.
This parameter is ensured by characterization and not 100% tested.
Test code range: 100 - 4000 codes, VREF = VDD, VDD = 5.5V.
Time delay to settle to a new reference when switching from external to internal reference or vice versa.
This parameter is indirectly tested by Offset and Gain error testing.
Within 1/2 LSB of the final value when code changes from 1/4 of to 3/4 of full scale.
This time delay is measured from the falling edge of ACK pulse in I2C command to the beginning of VOUT.
This time delay is not included in the output settling time specification.
DS22187E-page 6
© 2010 Microchip Technology Inc.
MCP4728
TFSCL
TRSCL
THIGH
TSU:STA
SCL
TLOW
SDA
THD:STA
TSP
THD:DAT
0.7VDD
0.3VDD
TAA
TFSDA
FIGURE 1-1:
TSU:STO
TBUF
TSU:DAT
TRSDA
I2C Bus Timing Data.
LDAC
TLDAC
0.7VDD
0.3VDD
VOUT (UDAC = 1)
No Update
FIGURE 1-2:
Update
LDAC Pin Timing vs. VOUT Update.
© 2010 Microchip Technology Inc.
DS22187E-page 7
MCP4728
I2C SERIAL TIMING SPECIFICATIONS
Electrical Specifications: Unless otherwise specified, all limits are specified for TA = -40 to +125°C, VSS = 0V,
Standard and Fast Mode: VDD = +2.7V to +5.5V
High Speed Mode: VDD = +4.5V to +5.5V.
Parameters
Clock Frequency
Bus Capacitive Loading
Start Condition Setup Time
(Start, Repeated Start)
Start Condition Hold Time
Stop Condition Setup Time
Clock High Time
Clock Low Time
Note 1:
2:
3:
4:
5:
Sym
Min
Typ
Max
Units
fSCL
0
—
100
kHz
Standard Mode
Cb = 400 pF, 2.7V – 5.5V
0
—
400
kHz
Fast Mode
Cb = 400 pF, 2.7V – 5.5V
0
—
1.7
MHz
High Speed Mode 1.7
Cb = 400 pF, 4.5V – 5.5V
0
—
3.4
MHz
High Speed Mode 3.4
Cb = 100 pF, 4.5V – 5.5V
—
—
400
pF
Standard Mode
2.7V – 5.5V
—
—
400
pF
Fast Mode
2.7V – 5.5V
—
—
400
pF
High Speed Mode 1.7
4.5V – 5.5V
—
—
100
pF
High Speed Mode 3.4
4.5V – 5.5V
Cb
TSU:STA
THD:STA
TSU:STO
THIGH
TLOW
4700
Conditions
—
ns
Standard Mode
600
—
—
ns
Fast Mode
160
—
—
ns
High Speed Mode 1.7
160
—
—
ns
High Speed Mode 3.4
4000
—
ns
Standard Mode
600
—
—
ns
Fast Mode
160
—
—
ns
High Speed Mode 1.7
160
—
—
ns
High Speed Mode 3.4
4000
—
ns
Standard Mode
600
—
—
ns
Fast Mode
160
—
—
ns
High Speed Mode 1.7
160
—
—
ns
High Speed Mode 3.4
4000
—
—
ns
Standard Mode
600
—
—
ns
Fast Mode
120
—
—
ns
High Speed Mode 1.7
60
—
—
ns
High Speed Mode 3.4
4700
—
—
ns
Standard Mode
1300
—
—
ns
Fast Mode
320
—
—
ns
High Speed Mode 1.7
160
—
—
ns
High Speed Mode 3.4
This parameter is ensured by characterization and is not 100% tested.
After a Repeated Start condition or an Acknowledge bit.
If this parameter is too short, it can create an unintentional Start or Stop condition to other devices on the I2C bus line. If
this parameter is too long, the Data Input Setup (TSU:DAT) or Clock Low time (TLOW) can be affected.
Data Input: This parameter must be longer than tSP.
Data Output: This parameter is characterized, and tested indirectly by testing TAA parameter.
This specification is not a part of the I2C specification. This specification is equivalent to the Data Hold Time (THD:DAT)
plus SDA Fall (or rise) time: TAA = THD:DAT + TFSDA (OR TRSDA).
Time between Start and Stop conditions.
DS22187E-page 8
© 2010 Microchip Technology Inc.
MCP4728
I2C SERIAL TIMING SPECIFICATIONS (CONTINUED)
Electrical Specifications: Unless otherwise specified, all limits are specified for TA = -40 to +125°C, VSS = 0V,
Standard and Fast Mode: VDD = +2.7V to +5.5V
High Speed Mode: VDD = +4.5V to +5.5V.
Parameters
SCL Rise Time
(Note 1)
SDA Rise Time
(Note 1)
SCL Fall Time
(Note 1)
SDA Fall Time
(Note 1)
Data Input Setup Time
Data Hold Time
(Input, Output)
(Note 3)
Output Valid from Clock
(Note 4)
Note 1:
2:
3:
4:
5:
Sym
TRSCL
TRSDA
TFSCL
TFSDA
TSU:DAT
THD:DAT
TAA
Min
Typ
Max
Units
Conditions
—
—
1000
ns
Standard Mode
20 + 0.1Cb
—
300
ns
Fast Mode
20
—
80
ns
High Speed Mode 1.7
20
—
160
ns
High Speed Mode 1.7
(Note 2)
10
—
40
ns
High Speed Mode 3.4
10
—
80
ns
High Speed Mode 3.4
(Note 2)
—
—
1000
ns
Standard Mode
20 + 0.1Cb
—
300
ns
Fast Mode
20
—
80
ns
High Speed Mode 1.7
10
—
40
ns
High Speed Mode 3.4
—
—
300
ns
Standard Mode
20 + 0.1Cb
—
300
ns
Fast Mode
20
—
80
ns
High Speed Mode 1.7
10
—
40
ns
High Speed Mode 3.4
—
—
300
ns
Standard Mode
20 + 0.1Cb
—
300
ns
Fast Mode
20
—
160
ns
High Speed Mode 1.7
10
—
80
ns
High Speed Mode 3.4
250
—
—
ns
Standard Mode
100
—
—
ns
Fast Mode
10
—
—
ns
High Speed Mode 1.7
10
—
—
ns
High Speed Mode 3.4
0
—
3450
ns
Standard Mode
0
—
900
ns
Fast Mode
0
—
150
ns
High Speed Mode 1.7
0
—
70
ns
High Speed Mode 3.4
0
—
3750
ns
Standard Mode
0
—
1200
ns
Fast Mode
0
—
310
ns
High Speed Mode 1.7
0
—
150
ns
High Speed Mode 3.4
This parameter is ensured by characterization and is not 100% tested.
After a Repeated Start condition or an Acknowledge bit.
If this parameter is too short, it can create an unintentional Start or Stop condition to other devices on the I2C bus line. If
this parameter is too long, the Data Input Setup (TSU:DAT) or Clock Low time (TLOW) can be affected.
Data Input: This parameter must be longer than tSP.
Data Output: This parameter is characterized, and tested indirectly by testing TAA parameter.
This specification is not a part of the I2C specification. This specification is equivalent to the Data Hold Time (THD:DAT)
plus SDA Fall (or rise) time: TAA = THD:DAT + TFSDA (OR TRSDA).
Time between Start and Stop conditions.
© 2010 Microchip Technology Inc.
DS22187E-page 9
MCP4728
I2C SERIAL TIMING SPECIFICATIONS (CONTINUED)
Electrical Specifications: Unless otherwise specified, all limits are specified for TA = -40 to +125°C, VSS = 0V,
Standard and Fast Mode: VDD = +2.7V to +5.5V
High Speed Mode: VDD = +4.5V to +5.5V.
Parameters
Bus Free Time
(Note 5)
Sym
Min
Typ
Max
Units
TBUF
4700
—
—
ns
Standard Mode
1300
—
—
ns
Fast Mode
—
—
—
ns
High Speed Mode 1.7
—
—
—
ns
High Speed Mode 3.4
—
—
—
ns
Standard Mode
(Not Applicable)
—
50
—
ns
Fast Mode
—
10
—
ns
High Speed Mode 1.7
—
10
—
ns
High Speed Mode 3.4
Input Filter
Spike Suppression
(SDA and SCL)
(Not Tested)
Note 1:
2:
3:
4:
5:
TSP
Conditions
This parameter is ensured by characterization and is not 100% tested.
After a Repeated Start condition or an Acknowledge bit.
If this parameter is too short, it can create an unintentional Start or Stop condition to other devices on the I2C bus line. If
this parameter is too long, the Data Input Setup (TSU:DAT) or Clock Low time (TLOW) can be affected.
Data Input: This parameter must be longer than tSP.
Data Output: This parameter is characterized, and tested indirectly by testing TAA parameter.
This specification is not a part of the I2C specification. This specification is equivalent to the Data Hold Time (THD:DAT)
plus SDA Fall (or rise) time: TAA = THD:DAT + TFSDA (OR TRSDA).
Time between Start and Stop conditions.
TEMPERATURE CHARACTERISTICS
Electrical Specifications: Unless otherwise indicated, VDD = +2.7V to +5.5V, VSS = GND.
Parameters
Symbol
Min
Typical
Max
Units
Specified Temperature Range
TA
-40
—
+125
°C
Operating Temperature Range
TA
-40
—
+125
°C
Storage Temperature Range
TA
-65
—
+150
°C
θJA
—
202
—
°C/W
Conditions
Temperature Ranges
Thermal Package Resistances
Thermal Resistance, 10L-MSOP
DS22187E-page 10
© 2010 Microchip Technology Inc.
MCP4728
2.0
TYPICAL PERFORMANCE CURVES
Note:
The graphs and tables provided following this note are a statistical summary based on a limited number of
samples and are provided for informational purposes only. The performance characteristics listed herein
are not tested or guaranteed. In some graphs or tables, the data presented may be outside the specified
operating range (e.g., outside specified power supply range) and therefore, outside the warranted range.
Note: Unless otherwise indicated, TA = -40°C to +125°C, VDD = +5.0V, VSS = 0V, RL = 5 kΩ, CL = 100 pF.
6
0.3
VDD = 5.5V, VREF = Internal, Gain = x1
0
-2
0
-0.2
-6
0
1024
FIGURE 2-1:
2048
Code
3072
0
4096
INL vs. Code (TA = +25°C).
6
1024
FIGURE 2-4:
0.3
VDD = 5.5V, VREF = Internal, Gain = x2
4
2048
Code
3072
4096
DNL vs. Code (TA = +25°C).
VDD = 5.5V, VREF = Internal, Gain = x2
0.2
2
DNL (LSB)
INL (LSB)
0.1
-0.1
-4
0
-2
0.1
0
-0.1
-4
-0.2
-6
0
1024
2048
Code
3072
0
4096
INL vs. Code (TA = +25°C).
FIGURE 2-2:
1024
2048
Code
2
0.1
DNL (LSB)
0.15
0
-2
4096
VDD = 5.5V, VREF = VDD
VDD = 5.5V, VREF = VDD
4
3072
DNL vs. Code (TA = +25°C).
FIGURE 2-5:
0.2
6
INL (LSB)
VDD = 5.5V, VREF = Internal, Gain = x1
0.2
2
DNL(LSB)
INL (LSB)
4
0.05
0
-0.05
-4
-6
-0.1
0
FIGURE 2-3:
1024
2048
Code
3072
4096
INL vs. Code (TA = +25°C).
© 2010 Microchip Technology Inc.
0
FIGURE 2-6:
1024
2048
Code
3072
4096
DNL vs. Code (TA = +25°C).
DS22187E-page 11
MCP4728
Note: Unless otherwise indicated, TA = -40°C to +125°C, VDD = +5.0V, VSS = 0V, RL = 5 kΩ, CL = 100 pF.
0.4
VDD = 2.7V, VREF = Internal, Gain = x1
4
0.3
2
0.2
DNL (LSB)
INL (LSB)
6
0
-2
0
-0.2
-6
0
1024
2048
Code
FIGURE 2-7:
3072
0
4096
INL vs. Code (TA = +25°C).
6
4
0.3
2
0.2
-2
2048
Code
3072
4096
DNL vs. Code (TA = +25°C).
0.4
VDD = 2.7V, VREF = VDD
0
1024
FIGURE 2-10:
DNL (LSB)
INL (LSB)
0.1
-0.1
-4
VDD = 2.7V, VREF = VDD
0.1
0
-0.1
-4
-0.2
-6
0
1024
2048
Code
3072
6
0
4096
INL vs. Code (TA = +25°C).
FIGURE 2-8:
o
-40 C
2
0.4
DNL(LSB)
0
-2
o
+25 C
-4
-6
o
+125 C
FIGURE 2-9:
Temperature.
DS22187E-page 12
4096
DNL vs. Code (TA = +25°C).
VDD = 5.5V, VREF = Internal, Gain = x1
0.2
0.1
0
+125oC
-0.2
1024
3072
-0.1
-10
0
2048
Code
0.3
+85°C
-8
1024
FIGURE 2-11:
VDD = 5.5V, VREF = Internal, Gain = x1
4
INL (LSB)
VDD = 2.7V, VREF = Internal, Gain = x1
2048
Code
3072
INL vs. Code and
4096
0
FIGURE 2-12:
Temperature.
- 40oC to +85oC
1024
2048
Code
3072
4096
DNL vs. Code and
© 2010 Microchip Technology Inc.
MCP4728
Note: Unless otherwise indicated, TA = -40°C to +125°C, VDD = +5.0V, VSS = 0V, RL = 5 kΩ, CL = 100 pF.
0.4
6
V DD = 5.5V, VREF = Internal, Gain = x2
4
o
- 40 C
o
o
+25 C
+85 C
0.2
DNL (LSB)
INL (LSB)
2
0
-2
-4
-8
0
-0.2
o
+125 C
-10
+125oC
- 40oC to +85oC
-0.3
0
1024
2048
Code
FIGURE 2-13:
Temperature.
3072
4096
0
0.5
VDD = 2.7V, VREF = Internal, Gain = x1
4
1024
FIGURE 2-16:
Temperature.
INL vs. Code and
6
2048
Code
3072
4096
DNL vs. Code and
VDD = 2.7V, VREF = Internal, Gain = x1
0.4
0.3
DNL (LSB)
2
INL (LSB)
0.1
-0.1
-6
0
-2
- 40oC
-4
o
+25 C
-6
+125 C
0
0
+125oC
-0.3
1024
FIGURE 2-14:
Temperature.
0.1
-0.2
o
-10
0.2
-0.1
+85oC
-8
2048
Code
3072
4096
INL vs. Code and
0
- 40oC to +85oC
1024
FIGURE 2-17:
Temperature.
2048
Code
3072
4096
DNL vs. Code and
0.4
6
VDD = 5.5V, VREF = VDD
VDD = 5.5V, VREF = VDD
0.3
4
+85oC
2
DNL (LSB)
INL (LSB)
VDD = 5.5V, VREF = Internal, Gain = x2
0.3
0
o
- 40 C
-2
-4
o
+125 C
0.2
0.1
0
-0.1
o
+25 C
-6
+125oC
- 40oC to +85oC
-0.2
0
FIGURE 2-15:
Temperature.
1024
2048
Code
3072
INL vs. Code and
© 2010 Microchip Technology Inc.
4096
0
FIGURE 2-18:
Temperature.
1024
2048
Code
3072
4096
DNL vs. Code and
DS22187E-page 13
MCP4728
Note: Unless otherwise indicated, TA = -40°C to +125°C, VDD = +5.0V, VSS = 0V, RL = 5 kΩ, CL = 100 pF.
0.5
6
VDD = 2.7V, VREF = V DD
4
- 40 oC
+85 C
0.3
DNL (LSB)
INL (LSB)
2
0
-2
o
+125 C
-4
0.1
0
-0.2
-8
0
1024
FIGURE 2-19:
Temperature.
2048
Code
3072
4096
INL vs. Code and
+125oC
-0.3
0
- 40oC to +85oC
1024
FIGURE 2-22:
Temperature.
2048
Code
3072
4096
DNL vs. Code and
6
-10
VDD = 2.7V, Gain = 1
-20
VDD = 5.5V, Gain = 1
-30
-40
5
Offset Error (mV)
Full Scale Error (mV)
0.2
-0.1
+25oC
-6
VDD = 5.5V, Gain = 2
4
3
VDD = 5.5V, Gain = 1
2
VDD = 2.7V, Gain = 1
1
VDD = 5.5V, Gain = 2
0
-50
-40 -25 -10
5
20 35 50 65 80
Temperature (oC)
-40 -25 -10
95 110 125
FIGURE 2-20:
Full Scale Error vs.
Temperature (Code = FFFh, VREF = Internal).
5
20 35 50 65 80
o
Temperature ( C)
95 110 125
FIGURE 2-23:
Zero Scale Error vs.
Temperature (Code = 000h, VREF = Internal).
4
50
VDD = 5.5V, Gain = 1
40
Offset Error (mV)
Full Scale Error (mV)
VDD = 2.7V, VREF = VDD
0.4
o
30
VDD = 2.7V, Gain = 1
20
3
VDD = 5.5V
2
VDD = 2.7V
1
0
10
-40 -25 -10
5
20 35 50 65 80
o
Temperature ( C)
95 110 125
FIGURE 2-21:
Full Scale Error vs.
Temperature (Code = FFFh, VREF = VDD).
DS22187E-page 14
-40 -25 -10
5
20
35
50
65
80
95 110 125
o
Temperature ( C)
FIGURE 2-24:
Error).
Offset Error (Zero Scale
© 2010 Microchip Technology Inc.
MCP4728
Note: Unless otherwise indicated, TA = -40°C to +125°C, VDD = +5.0V, VSS = 0V, RL = 5 kΩ, CL = 100 pF.
16
VREF = Internal, Gain = x2
2
o
Temp = +25 C
14
12
LSB
VOUT (2V/Div)
Ch. D
10
Ch. A
8
Ch. B
6
Ch. C
4
LDAC
2
Time (2 µs/Div)
0
0
500
FIGURE 2-25:
(VDD = 5.5V).
1000
1500 2000
Codes
2500
3000
3500
Absolute DAC Output Error
VOUT (2V/Div)
LDAC
Time (2 µs/Div)
FIGURE 2-26:
Full Scale Settling Time
(VREF = VDD, VDD = 5V, UDAC = 1,
Code Change: 000h to FFFh).
VOUT (2V/Div)
LDAC
Time (2 µs/Div)
FIGURE 2-27:
Half Scale Settling Time
(VREF = VDD, VDD = 5V, UDAC = 1,
Code Change: 000h to 7FFh).
© 2010 Microchip Technology Inc.
FIGURE 2-28:
Full Scale Settling Time
(VREF = Internal, VDD = 5V, UDAC = 1,
Gain = x1, Code Change: 000h to FFFh).
VOUT (2V/Div)
LDAC
Time (2 µs/Div)
FIGURE 2-29:
Full Scale Settling Time
(VREF = VDD, VDD = 5V, UDAC = 1,
Code Change: FFFh to 000h).
VOUT (2V/Div)
LDAC
Time (2 µs/Div)
FIGURE 2-30:
Half Scale Settling Time
(VREF = VDD, VDD = 5V, UDAC = 1,
Code Change: 7FFh to 000h).
DS22187E-page 15
MCP4728
Note: Unless otherwise indicated, TA = -40°C to +125°C, VDD = +5.0V, VSS = 0V, RL = 5 kΩ, CL = 100 pF.
Discharging Time due to
VOUT (1V/Div) internal pull-down resistor (500 kΩ)
VOUT (2V/Div)
Time (2 µs/Div)
LDAC
Time (10 µs/Div)
CLK
FIGURE 2-31:
Full Scale Settling Time
(VREF = Internal, VDD = 5V, UDAC = 1,
Gain = x1, Code Change: FFFh to 000h).
VOUT (1V/Div)
Time (2 µs/Div)
LDAC
FIGURE 2-32:
Half Scale Settling Time
(VREF = Internal, VDD = 5V, UDAC = 1,
Gain = x1, Code Change: 000h to 7FFh).
Last ACK CLK pulse
FIGURE 2-34:
Entering Power Down Mode
(Code: FFFh, VREF = Internal, VDD = 5V,
Gain = x1, PD1= PD0 = 1, No External Load).
VOUT (1V/Div)
Time (2 µs/Div)
LDAC
FIGURE 2-35:
Half Scale Settling Time
(VREF = Internal, VDD = 5V, UDAC = 1,
Gain = x1, Code Change: 7FFh to 000h).
VOUT (2V/Div)
VOUT (1V/Div)
TdExPD
TdExPD
Time (5 µs/Div)
Time (5 µs/Div)
CLK
Last ACK CLK pulse
FIGURE 2-33:
Exiting Power Down Mode
(Code: FFFh, VREF = Internal, VDD = 5V,
Gain = x1, for all Channels.).
DS22187E-page 16
CLK
Last ACK CLK pulse
FIGURE 2-36:
Exiting Power Down Mode
(Code: FFFh, VREF = VDD, VDD = 5V, for all
Channels).
© 2010 Microchip Technology Inc.
MCP4728
Note: Unless otherwise indicated, TA = -40°C to +125°C, VDD = +5.0V, VSS = 0V, RL = 5 kΩ, CL = 100 pF.
Discharging Time due to
internal pull-down resistor (500 kΩ)
VOUT at Channel D
(5V/Div)
VOUT (2V/Div)
LDAC
VOUT at Channel A
(100 mV/Div)
Time (5 µs/Div)
Time (20 µs/Div)
CLK
Last ACK CLK pulse
FIGURE 2-37:
Entering Power Down Mode
(Code: FFFh, VREF = VDD, VDD = 5V,
PD1= PD0 = 1, No External Load).
FIGURE 2-40:
Channel Cross Talk
(VREF = VDD, VDD = 5V).
VOUT (2V/Div)
VOUT (50 mV/Div)
Time (10 µs/Div)
Time (2 µs/Div)
CLK
Last ACK CLK pulse
FIGURE 2-38:
VOUT Time Delay when
VREF changes from Internal Reference to VDD.
FIGURE 2-41:
Code Change Glitch
(VREF = External, VDD = 5V, No External Load),
Code Change: 800h to 7FFh.
VOUT (2V/Div)
VOUT (50 mV/Div)
Time (2 µs/Div)
Time (10 µs/Div)
CLK
Last ACK CLK pulse
FIGURE 2-39:
VOUT Time Delay when
VREF changes from VDD to Internal Reference.
© 2010 Microchip Technology Inc.
FIGURE 2-42:
Code Change Glitch
(VREF = Internal, VDD = 5V, Gain = 1, No External
Load), Code Change: 800h to 7FFh.
DS22187E-page 17
MCP4728
Note: Unless otherwise indicated, TA = -40°C to +125°C, VDD = +5.0V, VSS = 0V, RL = 5 kΩ, CL = 100 pF.
900
6
5
VDD = 5V
VREF = VDD
Code = FFFh
3
2
700
VDD = 4.5V
VDD = 3.3V
600
VDD = 2.7V
1
500
0
0
1
2
3
Load Resistance (kΩ)
FIGURE 2-43:
-40 -25 -10
5
600
2 Channels On
400
200
35
50
65
80
95 110 125
VDD = 5.0V
All Channels On
800
IDD_INT (µA)
3 Channels On
20
FIGURE 2-46:
IDD vs. Temperature
(VREF = VDD, All channels are in Normal Mode,
Code = FFFh).
All Channels On
VDD = 5.0V
5
Temperature (oC)
1000
800
IDD_EXT (µA)
4
VOUT vs. Resistive Load.
1000
3 Channels On
600
2 Channels On
400
1 Channel On
200
1 Channel On
0
0
-40 -25 -10
5
20 35 50 65 80 95 110 125
-40 -25 -10
5
FIGURE 2-44:
IDD vs. Temperature
(VREF = VDD, VDD = 5V, Code = FFFh).
800
20 35 50 65 80 95 110 125
Temperature (oC)
o
Temperature ( C)
FIGURE 2-47:
IDD vs. Temperature
(VREF = Internal, VREF = 5V, Code = FFFh).
1000
VDD = 2.7V
V DD = 2.7V
All Channels On
400
2 Channels On
200
IDD_INT (µA)
3 Channels On
All Channels On
800
600
IDD_EXT (µA)
VDD = 5.5V
VDD = 5V
800
IDD_EXT (µA)
VOUT (V)
4
All Channels On
3 Channels On
600
2 Channels On
400
1 Channel On
200
1 Channel On
0
0
-40 -25 -10
5
20
35
50 65
80 95 110 125
o
Temperature ( C)
FIGURE 2-45:
IDD vs. Temperature
(VREF = VDD, VDD = 2.7V, Code = FFFh).
DS22187E-page 18
-40 -25 -10
5
20 35 50 65 80 95 110 125
Temperature (oC)
FIGURE 2-48:
IDD vs. Temperature
(VREF = Internal, VDD = 2.7V, Code = FFFh).
© 2010 Microchip Technology Inc.
MCP4728
Note: Unless otherwise indicated, TA = -40°C to +125°C, VDD = +5.0V, VSS = 0V, RL = 5 kΩ, CL = 100 pF.
900
6
VDD = 5.5V
All Channels On
Code = FFFh
5
VDD = 5V
VDD = 4.5V
700
VDD = 3.3V
VOUT (V)
IDD_INT (µA)
800
4
3
2
600
1
VDD = 2.7V
500
0
-40 -25 -10
5
20
35
50
65
80 95 110 125
0
2
4
6
o
Temperature ( C)
FIGURE 2-49:
IDD vs. Temperature
(VREF = Internal , All Channels are in Normal
Mode, Code = FFFh).
10
12
14
16
FIGURE 2-51:
Source Current Capability
(VREF = VDD, Code = FFFh).
6
60
Code = 000h
All Channels Off
50
VDD = 5V
5
VDD = 5.5V
VOUT (V)
IDDP_INT (µA)
8
Current (mA)
V DD = 4.5V
40
30
4
3
2
1
V DD = 3.3V
VDD = 2.7V
0
20
-40 -25 -10
5
20 35 50 65
o
Temperature ( C)
80
95 110 125
FIGURE 2-50:
IDD vs. Temperature
(VREF = Internal , All Channels are in Powered
Down).
© 2010 Microchip Technology Inc.
0
2
4
6
8
10
12
14
Sink Current (mA)
FIGURE 2-52:
Sink Current Capability
(VREF = VDD, Code = 000h).
DS22187E-page 19
MCP4728
NOTES:
DS22187E-page 20
© 2010 Microchip Technology Inc.
MCP4728
3.0
PIN DESCRIPTIONS
The descriptions of the pins are listed in Table 3-1.
TABLE 3-1:
Pin No.
PIN FUNCTION TABLE
Name
Pin Type
Function
1
VDD
P
Supply Voltage
2
SCL
OI
I2C Serial Clock Input (Note 1)
3
SDA
OI/OO
4
LDAC
ST
This pin is used for two purposes:
(a) Synchronization Input. It is used to transfer the contents of the DAC input
registers to the output registers (VOUT).
(b) Select the device for reading and writing I2C address bits. (Note 2)
5
RDY/BSY
OO
This pin is a status indicator of EEPROM programming activity. An external pull-up
resistor (about 100 kΩ) is needed from RDY/BSY pin to VDD line. (Note 1)
6
VOUT A
AO
Buffered analog voltage output of channel A. The output amplifier has rail-to-rail
operation.
7
VOUT B
AO
Buffered analog voltage output of channel B. The output amplifier has rail-to-rail
operation.
8
VOUT C
AO
Buffered analog voltage output of channel C. The output amplifier has rail-to-rail
operation.
9
VOUT D
AO
Buffered analog voltage output of channel D. The output amplifier has rail-to-rail
operation.
10
VSS
P
I2C Serial Data Input and Output (Note 1)
Ground reference.
Legend: P = Power, OI = Open-Drain Input, OO = Open-Drain Output, ST = Schmitt Trigger Input Buffer,
AO = Analog Output
Note 1: This pin needs an external pull-up resistor from VDD line. Leave this pin float if it is not used.
2: This pin can be driven by MCU.
3.1
Supply Voltage Pins (VDD, VSS)
VDD is the power supply pin for the device. The voltage
at the VDD pin is used as a power supply input as well
as a DAC external reference. The power supply at the
VDD pin should be as clean as possible for a good DAC
performance.
It is recommended to use an appropriate bypass
capacitor of about 0.1 µF (ceramic) to ground. An
additional 10 µF capacitor (tantalum) in parallel is also
recommended to further attenuate high-frequency
noise present in application boards. The supply voltage
(VDD) must be maintained in the 2.7V to 5.5V range for
specified operation.
VSS is the ground pin and the current return path of the
device. The user must connect the VSS pin to a ground
plane through a low-impedance connection. If an
analog ground path is available in the application
printed circuit board (PCB), it is highly recommended
that the VSS pin be tied to the analog ground path, or
isolated within an analog ground plane of the circuit
board.
© 2010 Microchip Technology Inc.
3.2
Serial Clock Pin (SCL)
SCL is the serial clock pin of the I2C interface. The
MCP4728 device acts only as a slave and the SCL pin
accepts only external input serial clocks. The input data
from the Master device is shifted into the SDA pin on
the rising edges of the SCL clock, and output from the
MCP4728 occurs at the falling edges of the SCL clock.
The SCL pin is an open-drain N-channel driver.
Therefore, it needs a pull-up resistor from the VDD line
to the SCL pin.
Refer to Section 5.0 “I2C Serial Interface
Communications” for more details on I2C Serial
Interface communication.
Typical range of the pull-up resistor value for SCL and
SDA is from 5 kΩ to 10 kΩ for Standard (100 kHz) and
Fast (400 kHz) modes, and less than 1 kΩ for High
Speed mode (3.4 MHz).
DS22187E-page 21
MCP4728
3.3
Serial Data Pin (SDA)
3.5
SDA is the serial data pin of the I2C interface. The SDA
pin is used to write or read the DAC register and
EEPROM data. Except for Start and Stop conditions,
the data on the SDA pin must be stable during the high
duration of the clock pulse. The High or Low state of the
SDA pin can only change when the clock signal on the
SCL pin is Low.
The SDA pin is an open-drain N-channel driver.
Therefore, it needs a pull-up resistor from the VDD line
to the SDA pin.
Refer to Section 5.0 “I2C Serial Interface
Communications” for more details on the I2C Serial
Interface communication.
3.4
LDAC Pin
This pin can be driven by an external control device
such as an MCU I/O pin. This pin is used to:
a)
b)
transfer the contents of the input registers to
their corresponding DAC output registers and
select a device of interest when reading or writing I2C address bits.
2C address
For more details on reading and writing the I
bits, see Section 5.4.4 “General Call Read Address
Bits” and Section 5.6.8 “Write Command: Write I2C
Address bits (C2=0, C1=1, C0=1)”.
RDY/BSY Status Indicator Pin
This pin is a status indicator of EEPROM programming
activity. This pin is “High” when the EEPROM has no
programming activity, and “Low” when the EEPROM is
in programming mode. It goes “High” when the
EEPROM program is completed.
The RDY/BSY pin is an open-drain N-channel driver.
Therefore, it needs a pull-up resistor (about 100 kΩ)
from the VDD line to the RDY/BSY pin. Let this pin float
if it is not used.
3.6
Analog Output Voltage Pins
(VOUT A, VOUT B, VOUT C, VOUT D)
The device has four analog voltage output (VOUT) pins.
Each output is driven by its own output buffer with a
gain of 1 or 2, depending on the gain and VREF
selection bit settings. In Normal mode, the DC
impedance of the output pin is about 1Ω. In
Power-Down mode, the output pin is internally
connected to 1 kΩ, 100 kΩ, or 500 kΩ, depending on
the Power-Down selection bit settings.
The VOUT pin can drive up to 1000 pF of capacitive
load. It is recommended to use a load with RL greater
than 5 kΩ.
When the logic status of the LDAC pin changes from
“High” to “Low”, the contents of all input registers
(Channels A – D) are transferred to their corresponding
output registers, and all analog voltage outputs are
updated simultaneously.
If this pin is permanently tied to “Low”, the content of
the input register is transferred to its output register
(VOUT) immediately at the last input data byte’s
acknowledge pulse.
The user can also use the UDAC bit instead. However,
the UDAC bit updates a selected channel only. See
Section 4.8 “Output Voltage Update” for more
information on the LDAC pin and UDAC bit functions.
DS22187E-page 22
© 2010 Microchip Technology Inc.
MCP4728
4.0
THEORY OF DEVICE
OPERATION
4.2
Reset Conditions
The device can be reset by two independent events:
The MCP4728 device is a 12-bit 4-channel buffered
voltage output DAC with nonvolatile memory
(EEPROM). The user can program the EEPROM with
I2C address bits, configuration and DAC input data of
each channel. The device has an internal charge pump
circuit to provide the programming voltage of the
EEPROM.
a)
b)
When the device is first powered-up, it automatically
loads the stored data in its EEPROM to the DAC input
and output registers, and provides analog outputs with
the saved settings immediately. This event does not
require an LDAC or UDAC bit condition. After the
device is powered-up, the user can update the input
registers using I2C write commands. The analog
outputs can be updated with new register values if the
LDAC pin or UDAC bit is low. The DAC output of each
channel is buffered with a low power and precision
output amplifier. This amplifier provides a rail-to-rail
output with low offset voltage and low noise.
The factory default settings for the EEPROM prior to
the device shipment are shown in Table 4-2.
The device uses a resistor string architecture. The
resistor ladder DAC can be driven from VDD or internal
VREF, depending on the reference selection. The user
can select internal (2.048V) or external reference (VDD)
for each DAC channel individually by software control.
The VDD is used as the external reference. Each
channel is controlled and operated independently.
The device has a Power-Down mode feature. Most of
the circuit in each powered down channel are turned
off. Therefore, operating power can be saved
significantly by putting any unused channel to the
Power-Down mode.
4.1
Power-on Reset (POR)
The device contains an internal Power-on Reset (POR)
circuit that monitors power supply voltage (VDD) during
operation. This circuit ensures correct device start-up
at system power-up and power-down events.
by Power-on Reset
by I2C General Call Reset Command
Under the reset conditions, the device uploads the
EEPROM data into both of the DAC input and output
registers simultaneously. The analog output voltage of
each channel is available immediately, regardless of
the LDAC and UDAC bit conditions.
4.3
Output Amplifier
The DAC output is buffered with a low power precision
amplifier. This amplifier provides low offset voltage and
low noise, as well as rail-to-rail output.
The output amplifier can drive the resistive and high
capacitive loads without oscillation. The amplifier can
provide a maximum load current of 24 mA, which is
enough for most of programmable voltage reference
applications. Refer to Section 1.0 “Electrical
Characteristics” for the specifications of the output
amplifier.
4.3.1
PROGRAMMABLE GAIN BLOCK
The rail-to-rail output amplifier of each channel has
configurable gain option. When the internal voltage
reference is selected, the output amplifier gain has two
selection options: Gain of 1 or Gain of 2.
When the external reference is selected (VREF = VDD),
the Gain of 2 option is disabled, and only the Gain of 1
is used by default.
4.3.1.1
Resistive and Capacitive Loads
The analog output (VOUT) pin is capable of driving
capacitive loads up to 1000 pF in parallel with 5 kΩ
load resistance. Figure 2-43 shows the VOUT vs.
Resistive Load.
If the power supply voltage is less than the POR
threshold (VPOR = 2V, typical), all circuits are disabled
and there will be no analog output. When the VDD
increases above the VPOR, the device takes a reset
state. During the reset period, each channel uploads all
configuration and DAC input codes from EEPROM,
and analog output (VOUT) will be available accordingly.
This enables the device to return to the same state that
it was at the last write to the EEPROM, before it was
powered off. The POR status is monitored by the POR
status bit by using the I2C read command. See
Figure 5-15 for the details of the POR status bit.
© 2010 Microchip Technology Inc.
DS22187E-page 23
MCP4728
4.4
DAC Input Registers and
Non-Volatile EEPROM Memory
Each channel has its own volatile DAC input register
and EEPROM. The details of the input registers and
EEPROM are shown in Table 4-1 and Table 4-2,
respectively.
TABLE 4-1:
INPUT REGISTER MAP (VOLATILE)
Configuration Bits
Bit
Name
RDY
/BSY
A2 A1 A0
VREF
DAC Input Data (12 bits)
DAC1 DAC0 PD1
PD0
GX
D11 D10 D9 D8
D7 D6 D5
Ref. DAC Channel Power-Down Gain
I2C
Select
Select
Address Bits Select
(Note 2)
(Note 2)
(Note 2)
(Note 1) (Note 2) (Note 2)
Bit
Function
D4
D3
D2
D1
D0
(Note 2)
CH. A
CH. B
CH. C
CH. D
Note 1:
2:
EEPROM write status indication bit (flag).
Loaded from EEPROM during power-up, or can be updated by the user.
TABLE 4-2:
EEPROM MEMORY MAP AND FACTORY DEFAULT SETTINGS
Configuration Bits
Bit Name
Bit
Function
CH. A
A2
A1
A0
I2C Address Bits
(Note 1)
0
DAC Input Data (12 bits)
PD0
Power-Down
Select
GX
D11
D10
D9
D8
D7
D6
D5
D4
D3
D2
D1
D0
Gain
Select
(Note 3)
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
CH. C
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
CH. D
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
2:
3:
0
Ref.
Select
(Note 2)
PD1
CH. B
Note 1:
0
VREF
Device I2C address bits. The user can also specify these bits during the device ordering process. The
factory default setting is “000”. These bits can be reprogrammed by the user using the I2C Address Write
command.
Voltage Reference Select: 0 = External VREF (VDD), 1 = Internal VREF (2.048V).
Gain Select: 0 = Gain of 1, 1 = Gain of 2.
DS22187E-page 24
© 2010 Microchip Technology Inc.
MCP4728
TABLE 4-3:
CONFIGURATION BITS
Bit Name
RDY/BSY
(A2, A1, A0)
VREF
DAC1, DAC0
Functions
This is a status indicator (flag) of EEPROM programming activity:
1 = EEPROM is not in programming mode
0 = EEPROM is in programming mode
Note: RDY/BSY status can also be monitored at the RDY/BSY pin.
Device I2C address bits. See Section 5.3 “MCP4728 Device Addressing” for more details.
Voltage Reference Selection bit:
0 = VDD
1 = Internal voltage reference (2.048V)
Note: Internal voltage reference circuit is turned off if all channels select external reference
(VREF = VDD).
DAC Channel Selection bits:
00 = Channel A
01 = Channel B
10 = Channel C
11 = Channel D
PD1, PD0
Power-Down selection bits:
00 = Normal Mode
01 = VOUT is loaded with 1 kΩ resistor to ground. Most of the channel circuits are powered off.
10 = VOUT is loaded with 100 kΩ resistor to ground. Most of the channel circuits are powered
off.
11 = VOUT is loaded with 500 kΩ resistor to ground. Most of the channel circuits are powered
off.
Note: See Table 4-7 and Figure 4-1 for more details.
GX
Gain selection bit:
0 = x1 (gain of 1)
1 = x2 (gain of 2)
Note: Applicable only when internal VREF is selected. If VREF = VDD, the device uses a gain of 1
regardless of the gain selection bit setting.
UDAC
DAC latch bit. Upload the selected DAC input register to its output register (VOUT):
0 = Upload. Output (VOUT) is updated.
1 = Do not upload.
Note: UDAC bit affects the selected channel only.
© 2010 Microchip Technology Inc.
DS22187E-page 25
MCP4728
4.5
Voltage Reference
The device has a precision internal voltage reference
which provides a nominal voltage of 2.048V. The user
can select the internal voltage reference or VDD as the
voltage reference source of each channel using the
VREF configuration bit. The internal voltage reference
circuit is turned off when all channels select VDD as
their references. However, it stays turned on if any one
of the channels selects the internal reference.
4.6
TABLE 4-4:
VREF
Internal
VREF
(2.048V)
VDD
Note 1:
The gain selection bit is not applicable
for VREF = VDD. In this case, Gain of 1
is used regardless of the gain selection
bit setting.
EQUATION 4-1:
VOUT =
Gain (GX)
Selection
LSB Size
Condition
x1
x2
0.5 mV
1 mV
2.048V/4096
4.096V/4096
x1
VDD/4096
(Note 1)
LSB size varies with the VDD range.
When VREF = VDD, the device uses
GX = 1 by default. GX = 2 option is
ignored.
DAC Output Voltage
The VDD needs to be as clean as possible for accurate
DAC performance. When the VDD is selected as the
voltage reference, any variation or noises on the VDD
line can directly affect on the DAC output.
The analog output of each channel has a
programmable gain block. The rail-to-rail output
amplifier has a configurable gain of 1 or 2. But the gain
of 2 is not applicable if VDD is selected for the voltage
reference. The formula for the analog output voltage is
given in Equation 4-1 and Equation 4-2.
OUTPUT VOLTAGE RANGE
VOUT FOR VREF =
INTERNAL REFERENCE
(VREF x Dn )
x Gx ≤ VDD
4096
Where:
VREF
Dn
Gx
LSB SIZES (EXAMPLE)
Each channel has an independent output associated
with its own configuration bit settings and DAC input
code. When the internal voltage reference is selected
(VREF = internal), it supplies the internal VREF voltage
to the resistor string DAC of the channel. When the
external reference (VREF=VDD) is selected, VDD is used
for the channel’s resistor string DAC.
4.7.1
Note:
LSB Size
The LSB is defined as the ideal voltage difference
between two successive codes. LSB sizes of the
MCP4728 device are shown in Table 4-4.
4.7
• When the external reference (VREF=VDD) is
selected:
- VOUT = 0.000V to VDD
=
=
=
2.048V for internal reference selection
DAC input code
Gain Setting
EQUATION 4-2:
VOUT FOR VREF = VDD
( V DD × D n )
VOUT = ----------------------------4096
Where:
Dn
4.8
=
DAC input code
Output Voltage Update
The following events update the output registers
(VOUT):
a.
b.
c.
d.
LDAC pin to “Low”: Updates all DAC channels.
UDAC bit to “Low”: Updates a selected channel
only.
General Call Software Update Command:
Updates all DAC channels.
Power-on Reset or General Call Reset
command: Both input and output registers are
updated with EEPROM data. All channels are
affected.
4.8.1
LDAC PIN AND UDAC BIT
The user can use the LDAC pin or UDAC bit to upload
the input DAC register to output DAC register (VOUT).
However, the UDAC affects only the selected channel
while the LDAC affects all channels. The UDAC bit is
not used in the Fast Mode Writing.
Table 4-5 shows the output update vs. LDAC pin and
UDAC bit conditions.
The DAC output voltage range varies depending on the
voltage reference selection.
• When the internal reference (VREF=2.048V) is
selected:
- VOUT = 0.000V to 2.048V * 4095/4096 for
Gain of 1
- VOUT = 0.000V to 4.096V * 4095/4096 for
Gain of 2
DS22187E-page 26
© 2010 Microchip Technology Inc.
MCP4728
TABLE 4-5:
LDAC Pin UDAC Bit
0
Update all DAC channel
outputs
0
1
Update all DAC channel
outputs
1
0
Update a selected DAC
channel output
1
1
No update
DAC Input Code Vs. DAC Analog
Output
Table 4-6 shows an example of the DAC input data
code vs. analog output. The MSB of the input data is
always transmitted first and the format is unipolar
binary.
DAC Output (VOUT)
0
TABLE 4-6:
4.9
LDAC AND UDAC
CONDITIONS VS. OUTPUT
UPDATE
DAC INPUT CODE VS. ANALOG OUTPUT (VOUT)
VREF = Internal (2.048 V)
DAC Input Code
Gain
Selection
Nominal Output Voltage (V)
(See Note 1)
111111111111
x1
VREF - 1 LSB
x2
2*VREF - 1 LSB
111111111110
x1
VREF - 2 LSB
x2
2*VREF - 2 LSB
000000000010
x1
2 LSB
000000000001
000000000000
Note 1:
x2
2 LSB
x1
1 LSB
x2
1 LSB
x1
0
x2
0
VREF = VDD
Gain
Selection
Ignored
Nominal Output Voltage (V)
VDD - 1 LSB
VDD - 2 LSB
2 LSB
1 LSB
0
(a) LSB with gain of 1 = 0.5 mV, and (b) LSB with gain of 2 = 1 mV.
© 2010 Microchip Technology Inc.
DS22187E-page 27
MCP4728
4.10
Normal and Power-Down Modes
Each channel has two modes of operation: (a) Normal
mode where analog voltage is available and (b)
Power-Down mode which turns off most of the internal
circuits for power savings.
The user can select the operating mode of each
channel individually by setting the Power-Down
selection bits (PD1 and PD0). For example, the user
can select Normal mode for channel A while selecting
Power-Down mode for all other channels.
See Section 5.6 “Write Commands for DAC
Registers and EEPROM” for more details on the
writing the power-down bits.
Most of the internal circuit in the powered down
channel are turned off. However, the internal voltage
reference circuit is not affected by the Power-Down
mode. The internal voltage reference circuit is turned
off only if all channels select external reference (VREF
= VDD).
Device actions during Power-Down mode:
• The powered down channel stays in a
power-saving condition by turning off most of its
circuits
• No analog voltage output at the powered down
channel
• The output (VOUT) pin of the powered down
channel is switched to a known resistive load. The
value of the resistive load is determined by the
state of the Power-Down bits (PD1 and PD0).
Table 4-7 shows the outcome of the Power-Down
bit settings
• The contents of both the DAC registers and
EEPROM are not changed
• Draws less than 40 nA (typical) when all four
channels are powered down and VDD is selected
as the voltage reference
Circuits that are not affected during Power-Down
mode:
• The I2C serial interface circuits remain active in
order to receive any command from the Master
• The internal voltage reference circuit stays
turned-on if it is selected as reference by at least
one channel
Exiting Power-Down Mode:
The device exits Power-Down mode immediately by
the following commands:
• Any write command for normal mode. Only
selected channel is affected
• I2C General Call Wake-Up Command. All
channels are affected
• I2C General Call Reset Command. This is a
conditional case. The device exits Power-Down
mode, depending on the Power-Down bit settings
in EEPROM as the configuration bits and DAC
input codes are uploaded from EEPROM. All
channels are affected
When the DAC operation mode is changed from the
Power-Down to Normal mode, there will be a time
delay until the analog output is available. Typical time
delay for the output voltage is approximately 4.5 µs.
This time delay is measured from the acknowledge
pulse of the I2C serial communication command to the
beginning of the analog output (VOUT). This time delay
is not included in the output settling time specification.
See Section 2.0 “Typical Performance Curves” for
more details.
TABLE 4-7:
PD1
POWER-DOWN BITS
PD0
0
0
1
Function
Normal Mode
1 kΩ resistor to ground (Note 1)
100 kΩ resistor to ground
(Note 1)
1
500 kΩ resistor to ground
(Note 1)
In Power-Down mode: VOUT is off and
most of internal circuits in the selected
channel are disabled.
0
1
0
1
Note 1:
VOUT
OP
Amp
Power-Down
Control Circuit
1 kΩ
100 kΩ 500 kΩ
Resistor String DAC
Resistive
Load
FIGURE 4-1:
Output Stage for
Power-Down Mode.
DS22187E-page 28
© 2010 Microchip Technology Inc.
MCP4728
5.0
I2C SERIAL INTERFACE
COMMUNICATIONS
The MCP4728 device uses a two-wire I2C serial
interface. When the device is connected to the I2C bus
line, the device works as a slave device. The device
supports standard, fast and high speed modes.
The following sections describe how to communicate
with the MCP4728 device using the I2C serial interface
commands.
5.1
Overview of I2C Serial Interface
Communications
An example of the hardware connection diagram is
shown in Figure 7-1. A device that sends data onto the
bus is defined as the transmitter, and a device receiving
data, as the receiver. The bus has to be controlled by a
master (MCU) device which generates the serial clock
(SCL), controls the bus access and generates the
START and STOP conditions. Both master (MCU) and
slave (MCP4728) can operate as transmitter or
receiver, but the master device determines which mode
is activated.
Communication is initiated by the master (MCU) which
sends the START bit, followed by the slave (MCP4728)
address byte. The first byte transmitted is always the
slave (MCP4728) address byte, which contains the
device code (1100), the address bits (A2, A1, A0), and
the R/W bit. The device code for the MCP4728 device
is 1100, and the address bits are user-writable.
When the MCP4728 device receives a Read command
(R/W = 1), it transmits the contents of the DAC input
registers and EEPROM sequentially. When writing to
the device (R/W = 0), the device will expect Write
command type bits in the following byte. The reading
and various writing commands are explained in the
following sections.
The MCP4728 device supports all three I2C serial
communication operating modes:
• Standard Mode: bit rates up to 100 kbit/s
• Fast Mode: bit rates up to 400 kbit/s
• High Speed Mode (HS mode): bit rates up to
3.4 Mbit/s
Refer to the Philips I2C document for more details of
the I2C specifications.
5.1.1
HIGH-SPEED (HS) MODE
2
The I C specification requires that a high-speed mode
device must be ‘activated’ to operate in High-Speed
(3.4 Mbit/s) mode. This is done by sending a special
address byte of 00001XXX following the START bit.
The XXX bits are unique to the high-speed mode
Master. This byte is referred to as the high-speed
Master Mode Code (HSMMC). The MCP4728 device
does not acknowledge this byte. However, upon
receiving this command, the device switches to HS
mode and can communicate at up to 3.4 Mbit/s on SDA
and SCL lines. The device will switch out of the HS
mode on the next STOP condition.
For more information on the HS mode, or other I2C
modes, please refer to the Philips I2C specification.
5.2
I2C BUS CHARACTERISTICS
The specification of the I2C serial communication
defines the following bus protocol:
• Data transfer may be initiated only when the bus
is not busy
• During data transfer, the data line must remain
stable whenever the clock line is HIGH. Changes
in the data line while the clock line is HIGH will be
interpreted as a START or STOP condition
Accordingly, the following bus conditions have been
defined using Figure 5-1.
5.2.1
BUS NOT BUSY (A)
Both data and clock lines remain HIGH.
5.2.2
START DATA TRANSFER (B)
A HIGH to LOW transition of the SDA line, while the
clock (SCL) is HIGH, determines a START condition.
All commands must be preceded by a START
condition.
5.2.3
STOP DATA TRANSFER (C)
A LOW to HIGH transition of the SDA line, while the
clock (SCL) is HIGH, determines a STOP condition. All
operations must be ended with a STOP condition.
5.2.4
DATA VALID (D)
The state of the data line represents valid data when,
after a START condition, the data line is stable for the
duration of the HIGH period of the clock signal.
The data on the line must be changed during the LOW
period of the clock signal. There is one clock pulse per
bit of data.
Each data transfer is initiated with a START condition
and terminated with a STOP condition.
© 2010 Microchip Technology Inc.
DS22187E-page 29
MCP4728
5.2.5
ACKNOWLEDGE
Each receiving device, when addressed, is obliged to
generate an acknowledge after the reception of each
byte. The master device must generate an extra clock
pulse, which is associated with this acknowledge bit.
The device that acknowledges has to pull down the
SDA line during the acknowledge clock pulse in such a
way that the SDA line is stable LOW during the HIGH
(A)
(B)
period of the acknowledge related clock pulse. Of
course, setup and hold times must be taken into
account. During reads, a master must send an end of
data to the slave by not generating an acknowledge bit
on the last byte that has been clocked out of the slave.
In this case, the slave (MCP4728) will leave the data
line HIGH to enable the master to generate the STOP
condition.
(D)
(D)
(C)
(A)
SCL
SDA
START
CONDITION
FIGURE 5-1:
5.3
ADDRESS OR
DATA
ACKNOWLEDGE ALLOWED
VALID
TO CHANGE
Data Transfer Sequence On The Serial Bus.
MCP4728 Device Addressing
The address byte is the first byte received following the
START condition from the master device. The first part
of the address byte consists of a 4-bit device code,
which is set to 1100 for the MCP4728 device. The
device code is followed by three I2C address bits (A2,
A1, A0) which are programmable by the users.
Although the three address bits are programmable at
the user’s application PCB, the user can also specify
the address bits during the product ordering process. If
there is no user’s request, the factory default setting of
the three address bits is “000”, programmed into the
EEPROM. The three address bits allow eight unique
addresses.
Acknowledge bit
Start bit
Read/Write bit
Slave Address
R/W ACK
Address Byte
Slave Address for MCP4728
Device Code
Address Bits
1
STOP
CONDITION
1
0
0
A2
A1 A0
5.3.1
PROGRAMMING OF I2C ADDRESS
BITS
When the customer first receives any new MCP4728
device, its default address bit setting is “000” if the
address bit programming was not requested. The
customer can reprogram the I2C address bits into the
EEPROM by using “Write Address Bit” command. This
write command needs current address bits. If the
address bits are unknown, the user can find them by
sending “General Call Read Address” Command. The
LDAC pin is also used to select the device of interest to
be programmed or to read the current address.
The following steps are needed for the I2C address
programming.
(a) Read the address bits using “General Call Read
Address” Command. (This is the case when the
address is unknown.)
(b) Write I2C address bits using “Write I2C Address
Bits” Command.
The Write Address command will replace the current
address with a new address in both input registers and
EEPROM.
See Section 5.4.4 “General Call Read Address Bits”
for the details of reading the address bits, and
Section 5.6.8 “Write Command: Write I2C Address
bits (C2=0, C1=1, C0=1)” for writing the address bits.
Device Code: Programmed (hard-wired) at the
factory.
Address Bits: Reprogrammable into EEPROM by
the user.
FIGURE 5-2:
DS22187E-page 30
Device Addressing.
© 2010 Microchip Technology Inc.
MCP4728
I2C General Call Commands
5.4
5.4.1
The General Call Reset occurs if the second byte is
“00000110” (06h). At the acknowledgement of this
byte, the device will abort the current conversion and
perform the following tasks:
The device acknowledges the general call address
command (0x00 in the first byte). The meaning of the
general call address is always specified in the second
byte. The I2C specification does not allow the use of
“00000000” (00h) in the second byte. Refer to the
Philips I2C document for more details of the General
Call specifications.
• Internal Reset similar to a Power-on Reset (POR).
The contents of the EEPROM are loaded into
each DAC input and output registers immediately
• VOUT will be available immediately regardless of
the LDAC pin condition
The MCP4728 device supports the following I2C
General Calls:
•
•
•
•
GENERAL CALL RESET
General Call Reset
General Call Wake-Up
General Call Software Update
General Call Read Address Bits
ACK (MCP4728)
Clock Pulse (CLK Line)
Stop
Start
1
2
3
4
5
6
7
8
9
1
2
3
4
5
6
7
8
2nd Byte
(Command Type = General Call Reset)
1st Byte
(General Call Command)
9
Note 1
Data (SDA Line)
Note 1:
At this falling edge of the last ACK clock bit:
a. Startup Timer starts a reset sequence and
b. EEPROM data is loaded into the DAC Input and Output Registers immediately.
FIGURE 5-3:
5.4.2
General Call Reset.
GENERAL CALL WAKE-UP
If the second byte is “00001001” (09h), the device will
reset the Power-Down bits (PD1, PD0 = 0,0).
ACK (MCP4728)
Clock Pulse (CLK Line)
Stop
Start
1
2
3
4
5
6
7
1st Byte
(General Call Command)
8
9
1
2
3
4
5
6
7
2nd Byte
(Command Type = General Call Wake-Up)
8
9
Note 1
Data (SDA Line)
Note 1:
Resets Power-Down bits at this falling edge of the last ACK clock bit.
FIGURE 5-4:
General Call Wake-Up.
© 2010 Microchip Technology Inc.
DS22187E-page 31
MCP4728
5.4.3
GENERAL CALL SOFTWARE
UPDATE
If the second byte is “00001000” (08h), the device
updates all DAC analog outputs (VOUT) at the same
time.
ACK (MCP4728)
Clock Pulse (CLK Line)
Start
1
2
3
4
5
Stop
6
7
8
9
1st Byte
(General Call Command)
1
2
3
4
5
6
7
8
2nd Byte
(Command Type = General Call Software Update)
9
Note 1
Data (SDA Line)
Note 1:
At this falling edge of the last ACK clock bit, VOUT A, VOUT B, VOUT C, VOUT D are updated.
FIGURE 5-5:
DS22187E-page 32
General Call Software Update.
© 2010 Microchip Technology Inc.
MCP4728
5.4.4
select the device of interest to read on the I2C bus. The
LDAC pin needs a logic transition from “High” to “Low”
during the negative pulse of the 8th clock of the second
byte, and stays “Low” until the end of the 3rd byte. The
maximum clock rate for this command is 400 kHz.
GENERAL CALL READ ADDRESS
BITS
This command is used to read the I2C address bits of
the device. If the second byte is “00001100” (0Ch), the
device will output its address bits stored in EEPROM
and register. This command uses the LDAC pin to
ACK (MCP4728)
ACK (Master)
Restart
Start
Stop
4th Byte
S 0 0 0 0 0 0 0 0 A 0 0 0 0 1 1 0 0 A Sr 1 1 0 0 X X X 1 A A2 A1 A0 1 A2 A1 A0 0 A P
1st Byte
(General Call Address)
2nd Byte
3rd Byte
Restart Byte
Address Bits Address Bits
in
in Input
EEPROM
Register
Reading Address Bits
LDAC Pin
(Notes 1, 2, 3)
Note 3
Clock and LDAC Transition Details:
ACK Clock
Clock Pulse
(CLK Line)
6
7
8
9
Restart Clock
Sr
1
2
ACK Clock
3
2nd Byte
4
5
6
3rd Byte
7
8
9
1
2
3
4th Byte
Reading Address Bits
Note 2(b, c)
LDAC Pin
Note 2 (a)
Note 2(b)
Note 3
Stay “Low” until the end of the 3rd Byte
Note 1:
2:
Clock Pulse and LDAC Transition Details.
LDAC pin events at the 2nd and 3rd bytes.
a.
b.
c.
Keep LDAC pin “High” until the end of the positive pulse of the 8th clock of the 2nd byte.
LDAC pin makes a transition from “High” to “Low” during the negative pulse of the 8th clock of the 2nd
byte (just before the rising edge of the 9th clock) and stays “Low” until the rising edge of clock 9 of the
3rd byte.
The MCP4728 device does not acknowledge the 3rd byte if the conditions (a) and (b) are not met.
3: LDAC pin resumes its normal function after “Stop” bit.
FIGURE 5-6:
General Call Read I2C Address.
© 2010 Microchip Technology Inc.
DS22187E-page 33
MCP4728
5.5
Writing and Reading Registers
and EEPROM
5.6
The Master (MCU) can write or read the DAC input
registers or EEPROM using the I2C interface
command.
The following sections describe the communication
examples to write and read the DAC registers and
EEPROM using the I2C interface.
TABLE 5-1:
Table 5-1 summarizes the write command types and
their functions.The write command is defined by using
three write command type bits (C2, C1, C0) and two
write function bits (W1, W0). The register selection bits
(DAC1, DAC0) are used to select the DAC channel.
WRITE COMMAND TYPES
Command Field
Write
Function
C2
W1
C1
Write Commands for DAC
Registers and EEPROM
C0
Command Name
Function
Fast Write for DAC
Input Registers
This command writes to the DAC input registers sequentially with
limited configuration bits. The data is sent sequentially from channels A
to D. The input register is written at the acknowledge clock pulse of the
channel’s last input data byte. EEPROM is not affected. (Note 1)
W0
Fast Mode Write
0
0
X
Not Used
Write DAC Input Register and EEPROM
0
1
0
0
0
Multi-Write for DAC
Input Registers
1
0
Sequential Write for
DAC Input Registers
and EEPROM
1
1
Single Write for DAC
Input Register and
EEPROM
This command writes to multiple DAC input registers, one DAC input
register at a time. The writing channel register is defined by the DAC
selection bits (DAC1, DAC0). EEPROM is not affected. (Note 2)
This command writes to both the DAC input registers and EEPROM
sequentially. The sequential writing is carried out from a starting
channel to channel D. The starting channel is defined by the DAC
selection bits (DAC1 and DAC0).
The input register is written at the acknowledge clock pulse of the last
input data byte of each register. However, the EEPROM data is written
altogether at the same time sequentially at the end of the last byte.
(Note 2),(Note 3)
This command writes to a single selected DAC input register and its
EEPROM. Both the input register and EEPROM are written at the
acknowledge clock pulse of the last input data byte. The writing
channel is defined by the DAC selection bits (DAC1 and DAC0).
(Note 2),(Note 3)
Write I2C Address Bits (A2, A1, A0)
0
1
1
Not Used
Write I2C Address Bits This command writes new I2C address bits (A2, A1, A0) to the DAC
input register and EEPROM.
Write VREF, Gain, and Power-Down Select Bits (Note 4)
0
0
Not Used
1
1
0
Not Used
Write Gain selection This command writes Gain selection bits of each channel.
bits to Input Registers
1
0
1
Not Used
Write Power-Down
This command writes Power-Down bits of each channel.
bits to Input Registers
Note 1:
2:
3:
4:
Write Reference
(VREF) selection bits
to Input Registers
This command writes Reference (VREF) selection bits of each channel.
1
The analog output is updated when LDAC pin is (or changes to) “Low”. UDAC bit is not used for this command.
The DAC output is updated when LDAC pin or UDAC bit is “Low”.
The device starts writing to the EEPROM on the acknowledge clock pulse of the last channel. The device does not
execute any command until RDY/BSY bit comes back to “High”.
The input and output registers are updated at the acknowledge clock pulse of the last byte. The update does not require
LDAC pin or UDAC bit conditions. EEPROM is not affected.
DS22187E-page 34
© 2010 Microchip Technology Inc.
MCP4728
5.6.1
FAST WRITE COMMAND
(C2=0, C1=0, C0=X, X = DON’T
CARE)
5.6.2
MULTI-WRITE COMMAND: WRITE
DAC INPUT REGISTERS
(C2=0, C1=1, C0=0; W1=0, W0=0)
The Fast Write command is used to update the input
DAC registers from channels A to D sequentially. The
EEPROM data is not affected by this command. This
command is called “Fast Write” because it updates the
input registers with only limited data bits. Only the
Power-Down mode selection bits (PD1 and PD0) and
12 bits of DAC input data are writable.
This command is used to write DAC input register, one
at a time. The EEPROM data is not affected by this
command.
The input register is updated at the acknowledge pulse
of each channel’s last data byte. Figure 5-7 shows an
example of the Fast Write command.
The D11 - D0 bits in the third and fourth bytes are the
DAC input data of the selected DAC channel.
Bytes 2 - 4 can be repeated for the other channels.
Figure 5-8 shows an example of the Multi-Write
command.
Updating Analog Outputs:
a.
b.
c.
When the LDAC pin is “High” before the last byte
of the channel D, all analog outputs are updated
simultaneously by bringing down the LDAC pin
to “Low” any time.
If the command starts with the LDAC pin “Low”,
the channel’s analog output is updated at the
falling edge of the acknowledge clock pulse of
the channel’s last byte.
Send the General Call Software Update
command: This command updates all channels
simultaneously.
Note:
The UDAC bit is not used in this
command.
© 2010 Microchip Technology Inc.
The DAC selection bits (DAC1, DAC0) select the DAC
channel to write. Only a selected channel is affected.
Repeated bytes are used to write more multiple DAC
registers.
Updating Analog Outputs:
The analog outputs can be updated by one of the
following events after the falling edge of the
acknowledge clock pulse of the 4th byte.
a.
b.
c.
When the LDAC pin or UDAC bit is “Low”.
If UDAC bit is “High”, bringing down the LDAC
pin to “Low” any time.
By sending the General Call Software Update
command.
Note:
The UDAC bit can be used effectively to
upload the input register to the output
register, but it affects only a selected
channel only, while the LDAC pin and
General Call Software Update command
affect all channels.
DS22187E-page 35
MCP4728
5.6.3
SEQUENTIAL WRITE COMMAND:
WRITE DAC INPUT REGISTERS
AND EEPROM SEQUENTIALLY
FROM STARTING CHANNEL TO
CHANNEL D
(C2=0, C1=1, C0=0; W1=1, W0=0)
When the device receives this command, it writes the
input data to the DAC input registers sequentially from
the starting channel to channel D, and also writes to
EEPROM sequentially. The starting channel is
determined by the DAC1 and DAC0 bits. Table 5-2
shows the functions of the channel selection bits for the
sequential write command.
When the device is writing EEPROM, the RDY/BSY bit
stays “Low” until the EEPROM write operation is
completed. The state of the RDY/BSY bit flag can be
monitored by a read command or at the RDY/BSY pin.
Any new command received during the EEPROM write
operation (RDY/BSY bit is “Low”) is ignored. Figure 5-9
shows an example of the sequential write command.
5.6.4
When the device receives this command, it writes the
input data to a selected single DAC input register and
also to its EEPROM. The channel is selected by the
channel selection bits (DAC1 and DAC0). See
Table 5-2 for the channel selection bit function.
Figure 5-10 shows an example of the single write
command.
Updating Analog Outputs:
The analog outputs can be updated by one of the
following events after the falling edge of the
acknowledge clock pulse of the 4th byte.
a.
b.
c.
Updating Analog Outputs:
The analog outputs can be updated by one of the
following events after the falling edge of the
acknowledge clock pulse of the 4th byte.
a.
b.
c.
When the LDAC pin or UDAC bit is “Low”.
If UDAC bit is “High”, bringing down the LDAC
pin to “Low” any time.
By sending the General Call Software Update
command.
Note:
SINGLE WRITE COMMAND: WRITE
A SINGLE DAC INPUT REGISTER
AND EEPROM
(C2=0, C1=1, C0=0; W1=1, W0=1)
When the LDAC pin or UDAC bit is “Low”.
If UDAC bit is “High”, bringing down the LDAC
pin to “Low” any time.
By sending the General Call Software Update
command.
Note:
The UDAC bit can be used effectively to
upload the input register to the output
register, but it affects only a selected
channel only, while the LDAC pin and
General Call Software Update command
affect all channels.
The UDAC bit can be used effectively to
upload the input register to the output
register, but it affects only a selected
channel only, while the LDAC pin and
General Call Software Update command
affect all channels.
TABLE 5-2:
DAC CHANNEL SELECTION
BITS FOR SEQUENTIAL
WRITE COMMAND
DAC1
DAC0
Channels
0
0
Ch. A - Ch. D
0
1
Ch. B - Ch. D
1
0
Ch. C - Ch. D
1
1
Ch. D
DS22187E-page 36
© 2010 Microchip Technology Inc.
MCP4728
5.6.5
WRITE COMMAND: SELECT VREF
BIT (C2=1, C1=0, C0=0)
When the device receives this command, it updates the
DAC voltage reference selection bit (VREF) of each
channel. The EEPROM data is not affected by this
command. The affected channel’s analog output is
updated after the acknowledge pulse of the last byte.
Figure 5-12 shows an example of the write command
for Select VREF bits.
5.6.6
WRITE COMMAND: SELECT
POWER-DOWN BITS (C2=1, C1=0,
C0=1)
When the device receives this command, it updates the
Power-Down selection bits (PD1, PD0) of each
channel. The EEPROM data is not affected by this
command. The affected channel is updated after the
acknowledge pulse of the last byte. Figure 5-13 shows
an example of the write command for the Select
Power-Down bits.
5.6.7
5.6.8
This command writes new I2C address bits (A2, A1,
A0) to the DAC input registers and EEPROM. When
the device receives this command, it overwrites the
current address bits with the new address bits.
This command is valid only when the LDAC pin makes
a transition from “High” to “Low” at the low time of the
last bit (8th clock) of the second byte, and stays “Low”
until the end of the third byte. The update occurs after
“Stop” bit, if the conditions are met. The LDAC pin is
used to select a device of interest to write. The highest
clock rate of this command is 400 kHz. Figure 5-11
shows the details of the address write command.
Note:
WRITE COMMAND: SELECT GAIN
BIT (C2=1, C1=1, C0=0)
When the device receives this command, it updates the
gain selection bits (GX) of each channel. The EEPROM
data is not affected by this command. The analog
output is updated after the acknowledge pulse of the
last byte. Figure 5-14 shows an example of the write
command for select gain bits.
5.6.9
To write a new device address, the current
address of the device is also required. If
the current address is not known, it can be
read out by sending General Call Read
Address Bits command. See 5.4.4
“General Call Read Address Bits” for
more details of reading the I2C address
bits.
READ COMMAND
If the R/W bit is set to a logic “High” in the I2C serial
communications command, the device enters a
reading mode and reads out the input registers and
EEPROM. Figure 5-15 shows the details of the read
command.
Note:
© 2010 Microchip Technology Inc.
WRITE COMMAND: WRITE I2C
ADDRESS BITS (C2=0, C1=1, C0=1)
The device address bits are read by using
General Call Read Address Bits
command.
DS22187E-page 37
MCP4728
Command Type Bits:
C2=0
C1=0
C0=X
ACK (MCP4728)
Start
S
1st byte
1
1
0
0
2nd Byte
(C2 C1)
A2 A1 A0
0
A
0
0 PD1 PD0 D11 D10 D9 D8 A D7 D6 D5 D4 D3 D2 D1 D0 A
R/W
Device Addressing
3rd Byte
DAC Input Register of Channel A
Fast Write
Command
Update Channel A DAC Input Register at this ACK pulse.
ACK (MCP4728)
3rd Byte
2nd Byte
X
X PD1 PD0 D11 D10 D9 D8 A D7 D6 D5 D4 D3 D2 D1 D0 A
DAC Input Register of Channel B
Update Channel B DAC Input Register at this ACK pulse.
ACK (MCP4728)
3rd Byte
2nd Byte
X
X PD1 PD0 D11 D10 D9 D8 A D7 D6 D5 D4 D3 D2 D1 D0 A
DAC Input Register of Channel C
Update Channel C DAC Input Register at this ACK pulse.
ACK (MCP4728)
3rd Byte
2nd Byte
X
X PD1 PD0 D11 D10 D9 D8 A D7 D6 D5 D4 D3 D2 D1 D0 A
DAC Input Register of Channel D
Update Channel D DAC Input Register at this ACK pulse.
Repeat Bytes
Note 1:
P
Stop
X is a don’t care bit. VOUT can be updated after the last byte’s ACK pulse is issued and by bringing down the LDAC
pin to “Low”.
FIGURE 5-7:
DS22187E-page 38
Fast Write Command: Write DAC Input Registers Sequentially from Channel A to D.
© 2010 Microchip Technology Inc.
MCP4728
Command Type Bits:
C2=0
C1=1
C0=0
W1=0
W0=0
ACK (MCP4728)
Start
1st byte
S
1
1
0
0
A2 A1 A0
0
A
R/W
Device Addressing
ACK (MCP4728)
(C2 C1 C0 W1 W2)
0
1
0
0
2nd Byte
3rd Byte
4th Byte
0 DAC1 DAC0 UDAC A VREF PD1 PD0 Gx D11 D10 D9 D8 A D7 D6 D5 D4 D3 D2 D1 D0 A
Multi-Write
Command
Channel
Select
DAC Input Register of Selected Channel
Note 1
Repeat Bytes of the 2nd - 4th Bytes
ACK (MCP4728)
2nd byte
X X X
X
Note 3
3rd Byte
4th Byte
X DAC1 DAC0 UDAC A VREF PD1 PD0 Gx D11 D10 D9 D8 A D7 D6 D5 D4 D3 D2 D1 D0 A
Channel
Select
Note 2
DAC Input Register of Selected Channel
Note 1
Repeat Bytes of the 2nd - 4th Bytes
P
Note 1:
Stop
VOUT Update:
2:
If UDAC = 0 or LDAC Pin = 0: VOUT is updated after the 4th byte’s ACK is issued.
The user can write to the other channels by sending repeated bytes with new channel selection bits (DAC1, DAC0).
3:
X is don’t care bit.
FIGURE 5-8:
Multi-Write Command: Write Multiple DAC Input Registers.
© 2010 Microchip Technology Inc.
DS22187E-page 39
MCP4728
Command Type Bits:
C2=0
C1=1
C0=0
W1=1
W0=0
ACK (MCP4728)
Start
S
1st byte
1
1
0
0
A2 A1 A0
0
A
R/W
Device Addressing
ACK (MCP4728)
2nd Byte
(C2 C1 C0 W1 W2)
0
1
0
1
3rd Byte
4th Byte
0 DAC1 DAC0 UDAC A VREF PD1 PD0 Gx D11 D10 D9 D8 A D7 D6 D5 D4 D3 D2 D1 D0 A
Sequential Write
Command
Sequential Write
Starting Channel
Select
DAC Input Register of Starting Channel
Note 1
Repeat Bytes of the 3rd - 4th Bytes
for the Starting Channel + 1, ... until Channel D.
ACK (MCP4728)
3rd Byte
Stop
4th Byte
VREF PD1 PD0 Gx D11 D10 D9 D8 A D7 D6 D5 D4 D3 D2 D1 D0 A
DAC Input Register of Channel D
(Last Channel)
Note 1:
2:
P
Notes 1 and 2
VOUT Update:
If UDAC = 0 or LDAC Pin = 0: VOUT is updated after the 4th byte’s ACK is issued.
EEPROM Write:
The MCP4728 device starts writing EEPROM at the falling edge of the 4th byte’s ACK pulse.
FIGURE 5-9:
Sequential Write Command: Write DAC Input Registers and EEPROM Sequentially
from Starting Channel to Channel D. The sequential input register starts with the "Starting Channel" and
ends at Channel D. For example, if DAC1:DAC0 = 00, then it starts with channel A and ends at channel D.
If DAC1:DAC0 = 01, then it starts with channel B and ends at Channel D. Note that this command can
send up to 10 bytes including the device addressing and command bytes. Any byte after the 10th byte is
ignored.
DS22187E-page 40
© 2010 Microchip Technology Inc.
MCP4728
Command Type Bits:
C2=0
C1=1
C0=0
W1=1
W0=1
ACK (MCP4728)
Start
S
1st byte
1
1
0
0
A2 A1 A0
0
A
R/W
Device Addressing
ACK (MCP4728)
C2 C1 C0 W1 W0
0
1
0
1
Single Write
Command
Note 1:
2:
2nd Byte
3rd Byte
Stop
4th Byte
1 DAC1 DAC0 UDAC A VREF PD1 PD0 Gx D11 D10 D9 D8 A D7 D6 D5 D4 D3 D2 D1 D0 A
Channel
Select
P
DAC Input Register of Selected Channel
Note 1 and Note 2
VOUT Update:
If UDAC = 0 or LDAC Pin = 0: VOUT is updated after the 4th byte’s ACK is issued.
EEPROM Write:
The MCP4728 device starts writing EEPROM at the falling edge of the 4th byte’s ACK pulse.
FIGURE 5-10:
Single Write Command: Write to a Single DAC Input Register and EEPROM.
© 2010 Microchip Technology Inc.
DS22187E-page 41
MCP4728
Command Type Bits:
Start
C2=0
C1=1
(C2 C1 C0)
1st Byte
C0=1
2nd Byte
S 1 1 0 0 A2 A1 A0 0 A 0 1 1 A2 A1 A0 0 1 A 0 1 1 A2 A1 A0 1 0 A 0
Device
Current R/W Command Current
Code Address Bits
Type Address Bits
Stop
4th Byte
3rd Byte
New
Command
Type Address Bits
1
1 A2 A1 A0 1 1 A P
Command New Address Bits
(for confirmation)
Type
Note 4
LDAC Pin
(Notes 1, 2, 3)
Note 3
Clock and LDAC Transition Details:
ACK (MCP4728)
Clock Pulse
(CLK Line)
Stop
5
6
7
8
9
1
2
3
4
5
6
3rd Byte
2nd Byte
7
8
9
1
-----
9
P
4th Byte
Note 4
Note 2(b)
LDAC Pin
Note 2(b)
Note 2 (a)
Note 3
Stay “Low” during this 3rd byte
Note 1:
2:
Clock Pulse and LDAC Transition Details.
LDAC pin events at the 2nd and 3rd bytes:
a.
b.
c.
3:
LDAC pin resumes its normal function after “Stop” bit.
4:
EEPROM Write:
a.
b.
FIGURE 5-11:
Note:
Keep LDAC pin “High” until the end of the positive pulse of the 8th clock of the 2nd byte.
LDAC pin makes a transition from “High” to “Low” during the negative pulse of the 8th clock of the 2nd byte
(just before the rising edge of the 9th clock), and stays “Low” until the rising edge of the 9th clock of the 3rd
byte.
The MCP4728 device does not acknowledge the 3rd byte if the conditions (a) and (b) are not met.
Charge Pump initiates the EEPROM write sequence at the falling edge of the 4th byte’s ACK pulse.
The RDY/BSY bit (pin) goes “Low” at the falling edge of this ACK clock and back to “High” immediately after
the EEPROM write is completed.
Write Command: Write I2C Address Bits to the DAC Registers and EEPROM.
The I2C address bits can also be programmed at the factory for customers. See the Product Identification System
on page 65 for details.
DS22187E-page 42
© 2010 Microchip Technology Inc.
MCP4728
Command Type Bits:
C2=1
C1=0
C0=0
ACK (MCP4728)
Start
S
1st byte
1
1
0
0
A2 A1 A0
0
A
1
0
0
Stop
2nd Byte
(C2 C1 C0)
X
VREF A VREF B VREF C VREF D
A
P
R/W
Device Addressing
Note 1:
2:
Write
Command
Note 1
Registers and VOUT are updated
at this falling edge of ACK pulse.
VREF = 0: VDD
= 1: Internal Reference (2.048V)
VREF A = Voltage reference of Channel A
VREF B = Voltage reference of Channel B
VREF C = Voltage reference of Channel C
VREF D = Voltage reference of Channel D
X is don’t care bit.
FIGURE 5-12:
Registers.
Write Command: Write Voltage Reference Selection Bit (VREF) to the DAC Input
Command Type Bits:
C2=1
C1=0
C0=1
ACK (MCP4728)
Start
S
1st byte
1
1
0
0
A2 A1 A0
0
A
R/W
Device Addressing
Stop
ACK (MCP4728)
(C2 C1 C0)
1
0
1
X
PD1 A PD0 A PD1 B PD0 B A
Write Command Channel A
for Power-Down
Selection Bits
Note 1:
3rd Byte
2nd Byte
Channel B
PD1 C
PD0 C PD1 D
Channel C
PD0 D
X
X
X
X
A
P
Channel D
Registers and VOUT are updated
at this falling edge of ACK pulse.
X is don’t care bit.
FIGURE 5-13:
Write Command: Write Power-Down Selection Bits (PD1, PD0) to the DAC Input
Registers. See Table 4-7 for the power-down bit setting.
© 2010 Microchip Technology Inc.
DS22187E-page 43
MCP4728
Command Type Bits:
C2=1
C1=1
C0=0
ACK (MCP4728)
Start
S
1st Byte
1
1
0
0
A2
(C2 C1 C0)
A1
A0
Device Addressing
0
R/W
A
1
1
0
2nd Byte
X
Write Command
for Gain Selection Bits
GX A GX B GX C GX D
Stop
A
P
Note 1
Registers and VOUT are updated
at this falling edge of ACK pulse.
Note 1:
GX A = Gain Selection for Channel A
GX B = Gain Selection for Channel B
GX C = Gain Selection for Channel C
GX D = Gain Selection for Channel D
Ex: GX A = 0: Gain of 1 for Channel A
= 1: Gain of 2 for Channel A
2:
X is don’t care bit.
FIGURE 5-14:
DS22187E-page 44
Write Command: Write Gain Selection Bit (GX) to the DAC Input Registers.
© 2010 Microchip Technology Inc.
MCP4728
ACK (MCP4728)
Read Command
Start
S
1
1
0
0
A2 A1 A0
1
A
R/W
Device Code
Address Bits
ACK (MASTER)
2nd Byte
RDY/
BSY
POR DAC1 DAC 0 0
3rd Byte
A2 A1 A0 A
VREF
4th Byte
Stop
PD1 PD0 GX D11 D10 D9 D8 A D7 D6 D5 D4 D3 D2 D1 D0 A P
Channel A DAC Input Register
5th Byte
RDY/
BSY
POR DAC1 DAC 0 0
6th Byte
A2 A1 A0 A
VREF
7th Byte
Stop
PD1 PD0 GX D11 D10 D9 D8 A D7 D6 D5 D4 D3 D2 D1 D0 A P
Channel A DAC EEPROM
2nd Byte
RDY/
BSY
POR DAC1 DAC 0 0
3rd Byte
A2 A1 A0 A
VREF
4th Byte
Stop
PD1 PD0 GX D11 D10 D9 D8 A D7 D6 D5 D4 D3 D2 D1 D0 A P
Channel B DAC Input Register
5th Byte
RDY/
BSY
POR DAC1 DAC 0 0
6th Byte
A2 A1 A0 A
VREF
7th Byte
Stop
PD1 PD0 GX D11 D10 D9 D8 A D7 D6 D5 D4 D3 D2 D1 D0 A P
Channel B DAC EEPROM
2nd Byte
RDY/
BSY
POR DAC1 DAC 0 0
3rd Byte
A2 A1 A0 A
VREF
4th Byte
Stop
PD1 PD0 GX D11 D10 D9 D8 A D7 D6 D5 D4 D3 D2 D1 D0 A P
Channel C DAC Input Register
5th Byte
RDY/
BSY
POR DAC1 DAC 0 0
6th Byte
A2 A1 A0 A
VREF
7th Byte
Stop
PD1 PD0 GX D11 D10 D9 D8 A D7 D6 D5 D4 D3 D2 D1 D0 A P
Channel C DAC EEPROM
2nd Byte
RDY/
BSY
POR DAC1 DAC 0 0
3rd Byte
A2 A1 A0 A
VREF
4th Byte
Stop
PD1 PD0 GX D11 D10 D9 D8 A D7 D6 D5 D4 D3 D2 D1 D0 A P
Channel D DAC Input Register
5th Byte
RDY/
BSY
POR DAC1 DAC 0 0
A2 A1 A0 A
6th Byte
VREF
Stop
PD1 PD0 GX D11 D10 D9 D8 A D7 D6 D5 D4 D3 D2 D1 D0 A P
Channel D DAC EEPROM
Note 1:
7th Byte
Repeat
The 2nd - 4th bytes are the contents of the DAC Input Register and the 5th - 7th bytes are the EEPROM contents.
The device outputs sequentially from channel A to D.
POR Bit: 1 = Set (Device is powered on with VDD > VPOR), 0 = Powered off state.
FIGURE 5-15:
Read Command and Device Outputs.
© 2010 Microchip Technology Inc.
DS22187E-page 45
MCP4728
NOTES:
DS22187E-page 46
© 2010 Microchip Technology Inc.
MCP4728
6.0
TERMINOLOGY
6.1
Resolution
The resolution is the number of DAC output states that
divide the full scale range. For the 12-bit DAC, the
resolution is 212, meaning the DAC code ranges from 0
to 4095.
6.2
Least Significant Bit (LSB)
7
INL = < -1 LSB
6
INL = - 1 LSB
5
Analog 4
Output
(LSB) 3
INL = 0.5 LSB
2
The least significant bit is the ideal voltage difference
between two successive codes.
1
EQUATION 6-1:
0
000 001 010
V REF
LSB = -----------n
2
Ideal Transfer Function
( V Full Scale – V Zero Scale )
= --------------------------------------------------------12
2 –1
( V Full Scale – V Zero Scale )
= --------------------------------------------------------4095
Where:
VREF
=
=
n
6.3
=
VDD
If external reference is
selected
2.048V If internal reference is
selected
The number of digital input bits,
n = 12 for MCP4728
Integral Nonlinearity (INL)
Integral nonlinearity (INL) error is the maximum
deviation of an actual transfer function from an ideal
transfer function (straight line). In the MCP4728, INL is
calculated using two end-points (zero and full scale).
INL can be expressed as a percentage of full scale
range (FSR) or in fractions of an LSB. INL is also called
relative accuracy. Equation 6-2 shows how to calculate
the INL error in LSB and Figure 6-1 shows an example
of INL accuracy.
EQUATION 6-2:
011 100 101 110 111
DAC Input Code
Actual Transfer Function
FIGURE 6-1:
6.4
INL Accuracy.
Differential Nonlinearity (DNL)
Differential nonlinearity (DNL) error (see Figure 6-2) is
the measure of step size between codes in actual
transfer function. The ideal step size between codes is
1 LSB. A DNL error of zero would imply that every code
is exactly 1 LSB wide. If the DNL error is less than
1 LSB, the DAC guarantees monotonic output and no
missing codes. The DNL error between any two
adjacent codes is calculated as follows:
EQUATION 6-3:
DNL ERROR
ΔV OUT – LSB
DNL = ---------------------------------LSB
Where:
DNL is expressed in LSB.
ΔVOUT
=
The measured DAC output
voltage difference between two
adjacent input codes
INL ERROR
( V OUT – V Ideal )
INL = --------------------------------------LSB
Where:
INL is expressed in LSB
=
Code*LSB
VIdeal
VOUT
=
The output voltage measured at
the given input code
© 2010 Microchip Technology Inc.
DS22187E-page 47
MCP4728
7
DNL = 0.5 LSB
6
5
DNL = 2 LSB
Analog 4
Output
(LSB) 3
For the MCP4728 device, the gain error is not
calibrated at the factory and most of the gain error is
contributed by the output buffer (op amp) saturation
near the code range beyond 4000. For applications that
need the gain error specification less than 1%
maximum, a user may consider using the DAC code
range between 100 and 4000 instead of using full code
range (code 0 to 4095). The DAC output of the code
range between 100 and 4000 is much more linear than
full scale range (0 to 4095). The gain error can be
calibrated out by using applications’ software.
2
6.7
1
0
000 001 010
011 100 101 110 111
DAC Input Code
Full Scale Error (FSE)
Full scale error (see Figure 6-4) is the sum of offset
error plus gain error. It is the difference between the
ideal and measured DAC output voltage with all bits set
to one (DAC input code = FFFh).
Ideal Transfer Function
Actual Transfer Function
FIGURE 6-2:
6.5
EQUATION 6-4:
( V OUT – V Ideal )
FSE = --------------------------------------LSB
DNL Accuracy.
Where:
Offset Error
Offset error (see Figure 6-3) is the deviation from zero
voltage output when the digital input code is zero (zero
scale voltage). This error affects all codes by the same
amount. For the MCP4728 device, the offset error is
not trimmed at the factory. However, it can be calibrated
by software in application circuits.
FSE is expressed in LSB.
VIdeal = (VREF) (1 - 2-n) - Offset Voltage (VOS)
VREF = Voltage Reference
Actual Transfer Function
Actual Transfer Function
Full Scale
Error
Analog
Gain Error
Output
Analog
Output
Offset
Error
Ideal Transfer Function
0
FIGURE 6-3:
6.6
Actual Transfer Function
after Offset Error is removed
Ideal Transfer Function
DAC Input Code
Gain Error
Gain error (see Figure 6-4) is the difference between
the actual full scale output voltage from the ideal output
voltage of the DAC transfer curve. The gain error is
calculated after nullifying the offset error, or full scale
error minus the offset error.
The gain error indicates how well the slope of the actual
transfer function matches the slope of the ideal transfer
function. The gain error is usually expressed as percent
of full scale range (% of FSR) or in LSB.
DS22187E-page 48
0
Offset Error.
DAC Input Code
FIGURE 6-4:
Error.
6.8
Gain Error and Full Scale
Gain Error Drift
Gain error drift is the variation in gain error due to a
change in ambient temperature. The gain error drift is
typically expressed in ppm/°C.
© 2010 Microchip Technology Inc.
MCP4728
6.9
Offset Error Drift
Offset error drift is the variation in offset error due to a
change in ambient temperature. The offset error drift is
typically expressed in ppm/oC.
6.10
Settling Time
The Settling time is the time delay required for the DAC
output to settle to its new output value from the start of
code transition, within specified accuracy. In the
MCP4728 device, the settling time is a measure of the
time delay until the DAC output reaches its final value
within 0.5 LSB when the DAC code changes from 400h
to C00h.
6.11
Major-Code Transition Glitch
Major-code transition glitch is the impulse energy
injected into the DAC analog output when the code in
the DAC register changes state. It is normally specified
as the area of the glitch in nV-Sec. and is measured
when the digital code is changed by 1 LSB at the major
carry transition (Example: 011...111 to 100...
000, or 100... 000 to 011... 111).
6.12
Digital Feedthrough
Digital feedthrough is a glitch that appears at the
analog output caused by coupling from the digital input
pins of the device. The area of the glitch is expressed
in nV-Sec, and is measured with a full scale change
(Example: all 0s to all 1s and vice versa) on the digital
input pins. The digital feedthrough is measured when
the DAC is not being written to the output register. This
condition can be created by writing the input register
with both the UDAC bit and the LDAC pin high.
© 2010 Microchip Technology Inc.
6.13
Analog Crosstalk
Analog crosstalk is a glitch that appears at the output of
one DAC due to a change in the output of the other
DAC. The area of the glitch is expressed in nV-Sec,
and measured by loading one of the input registers with
a full scale code change (all 0s to all 1s and vice versa)
while keeping both the UDAC bit and the LDAC pin
high. Then bring down the LDAC pin to low and measure the output of the DAC whose digital code was not
changed.
6.14
DAC-to-DAC Crosstalk
DAC-to-DAC crosstalk is the glitch that appears at the
output of one DAC due to an input code change and
subsequent output change of the other DAC. This
includes both digital and analog crosstalks. The area of
the glitch is expressed in nV-Sec, and measured by
loading one of the input registers with a full scale code
change (all 0s to all 1s and vice versa) while keeping
UDAC bit or LDAC pin low.
6.15
Power-Supply Rejection Ratio
(PSRR)
PSRR indicates how the output of the DAC is affected
by changes in the supply voltage. PSRR is the ratio of
the change in VOUT to a change in VDD for full scale
output of the DAC. It is measured on one DAC that is
using an internal VREF while the VDD is varied ±10%,
and expressed in dB or µV/V.
DS22187E-page 49
MCP4728
NOTES:
DS22187E-page 50
© 2010 Microchip Technology Inc.
MCP4728
7.0
TYPICAL APPLICATIONS
7.1
The MCP4728 device is a part of Microchip’s latest
DAC family with nonvolatile EEPROM memory. The
device is a general purpose resistor string DAC
intended to be used in applications where a precise
and low power DAC, with moderate bandwidth, is
required.
The SCL, SDA, and RDY/BSY pins of the MCP4728
device are open-drain configurations. These pins
require a pull-up resistor, as shown in Figure 7-1. The
LDAC pin has a Schmitt trigger input configuration and
it can be driven by an external MCU I/O pin.
Since the device includes nonvolatile EEPROM
memory, the user can use this device for applications
that require the output to return to the previous set-up
value on subsequent power-ups.
The pull-up resistor values (R1 and R2) for SCL and
SDA pins depend on the operating speed (standard,
fast, and high speed) and loading capacitance of the
I2C bus line. Higher value of pull-up resistor consumes
less power, but increases the signal transition time
(higher RC time constant) on the bus line. Therefore, it
can limit the bus operating speed. A lower resistor
value, on the other hand, consumes higher power, but
allows for higher operating speed. If the bus line has
higher capacitance due to long metal traces or multiple
device connections to the bus line, a smaller pull-up
resistor is needed to compensate for the long RC time
constant. The pull-up resistor is typically chosen
between 1 kΩ and 10 kΩ range for standard and fast
modes, and less than 1 kΩ for high speed mode.
Applications generally suited for the MCP4728 device
family include:
•
•
•
•
Connecting to I2C BUS Using
Pull-Up Resistors
Set Point or Offset Trimming
Sensor Calibration
Portable Instrumentation (Battery Powered)
Motor Speed Control
VDD
C1
C2
R1
R2
R3
VSS
VDD 1
10
SCL 2
9 VOUT D
SDA 3
MCP4728
8 VOUT C
LDAC 4
7 VOUT B
RDY/BSY 5
6 VOUT A
Analog Outputs
To MCU
R1 and R2 = Pull-up resistors for I2C Serial Communications
R3
= 5 kΩ - 10 kΩ for fSCL = 100 kHz to 400 kHz
= ~700Ω for fSCL = 3.4 MHz
= (a) Pull-up resistor to monitor RDY/BSY bit = ~ 100 kΩ
(b) Let this pin float when not used
C1 = 0.1 µF, Ceramic capacitor
C2 = 10 µF, Tantalum capacitor
FIGURE 7-1:
Example of the MCP4728 Device Connection.
© 2010 Microchip Technology Inc.
DS22187E-page 51
MCP4728
7.1.1
7.3
DEVICE CONNECTION TEST
The user can test the presence of the MCP4728 device
on the I2C bus line without performing a data
conversion. This test can be achieved by checking an
acknowledge response from the MCP4728 device after
sending a read or write command. Figure 7-2 shows an
example with a read command:
Set the R/W bit “High” or “Low” in the address
byte.
Check the ACK pulse after sending the address
byte.
If the device acknowledges (ACK = 0) the
command, then the device is connected,
otherwise it is not connected.
Send Stop Bit.
a.
b.
c.
Address Byte
SDA
Start
Bit
1
2
3
4
5
6
7
8
1
1
0
1 A2 A1 A0 1
9
Stop
Bit
Device Code Address bits
R/W
MCP4728
Response
FIGURE 7-2:
7.2
I2C Bus Connection Test.
Layout Considerations
Inductively-coupled AC transients and digital switching
noise from other devices can affect DAC performance
and DAC output signal integrity. Careful board layout
will minimize these effects. Bench testing has shown
that a multi-layer board utilizing a low-inductance
ground plane, isolated inputs, isolated outputs and
proper decoupling are critical to achieving good DAC
performance.
Separate digital and analog ground planes are
recommended. In this case, the VSS pin and the ground
pins of the VDD capacitors of the MCP4728 should be
terminated to the analog ground plane.
DS22187E-page 52
The power source should be as clean as possible. The
power supply to the device is used for both VDD and
DAC voltage reference by selecting VREF = VDD. Any
noise induced on the VDD line can affect DAC
performance. A typical application will require a bypass
capacitor in order to filter out high-frequency noise on
the VDD line. The noise can be induced onto the power
supply’s traces or as a result of changes on the DAC
output. The bypass capacitor helps to minimize the
effect of these noise sources on signal integrity.
Figure 7-1 shows an example of using two bypass
capacitors (a 10 µF tantalum capacitor and a 0.1 µF
ceramic capacitor) in parallel on the VDD line. These
capacitors should be placed as close to the VDD pin as
possible (within 4 mm). If the application circuit has
separate digital and analog power supplies, the VDD
and VSS pins of the MCP4728 device should reside on
the analog plane.
7.4
ACK
SCL
Power Supply Considerations
Using Power Saving Feature
The device consumes very little power when it is in
Power-Down (shut-down) mode. During the
Power-Down mode, most circuits in the selected
channel are turned off. It is recommended to power
down any unused channel.
The device consumes the least amount of power if it
enters the Power-Down mode after the internal voltage
reference is disabled. This can be achieved by
selecting VDD as the voltage reference for all 4
channels, and then issuing the Power-Down mode for
all channels.
7.5
Using Nonvolatile EEPROM
Memory
The user can store the I2C device address bits,
configuration bits and DAC input code of each channel
in the on-board nonvolatile EEPROM memory using
the I2C write command. The contents of EEPROM are
readable and writable using the I2C command.
When the MCP4728 device is first powered-up or
receives General Call Reset Command, it uploads the
EEPROM contents to the DAC output registers
automatically and provides analog outputs immediately
with the saved settings in EEPROM. This feature is
very useful in applications where the MCP4728 device
is used to provide set points or calibration data for other
devices in the application systems. The MCP4728
device can save important system parameters when
the application system experiences power failure. See
Section 5.5 “Writing and Reading Registers and
EEPROM” for more details on using the nonvolatile
EEPROM memory.
© 2010 Microchip Technology Inc.
MCP4728
7.6
Application Examples
The MCP4728 device is a rail-to-rail output DAC
designed to operate with a VDD range of 2.7V to 5.5V.
Its output amplifier of each channel is robust enough to
drive common, small-signal loads directly, thus
eliminating the cost and size of external buffers for
most applications. Since each channel has its own
configuration bits for selecting the voltage reference,
gain, power-down, etc., the MCP4728 device offers
great simplicity and flexibility to use for various DAC
applications.
7.6.1
DC SET POINT OR CALIBRATION
VOLTAGE SETTINGS
A common application for the MCP4728 device is a
digitally-controlled set point or a calibration of variable
parameters such as sensor offset or bias point.
Figure 7-3 shows an example of the set point settings.
Let us consider that the application requires different
trip voltages (Trip 1 - Trip 4). Assuming the DAC output
voltage requirements are given as shown in Table 7-1,
examples of sending the Sequential Write and Fast
Write commands are shown in Figure 7-4 and
Figure 7-5.
TABLE 7-1:
© 2010 Microchip Technology Inc.
EXAMPLE: SETTING VOUT OF
EACH CHANNEL
DAC Channel
Voltage
Reference
DAC Output
(VOUT)
VOUT A
VDD
VDD/2
VOUT B
VDD
VDD - 1 LSB
VOUT C
Internal
2.048V
VOUT D
Internal
4.096V
DS22187E-page 53
MCP4728
VDD
Light
Comparator 1
RSENSE
R1
VTRIP1
R2
0.1 µF
VDD
Light
Comparator 2
RSENSE
VDD
0.1 µF
10 µF
R1
VTRIP2
R1
R2
R3
R4
R2
VDD 1
10
SCL 2
9 VOUT D
SDA 3
MCP4728
0.1 µF
VSS
8 VOUT C
LDAC 4
7 VOUT B
RDY/BSY 5
6 VOUT A
VDD
Light
Analog Outputs
Comparator 3
RSENSE
R1
VTRIP3
To MCU
R2
0.1 µF
VDD
Light
D n = Input Code (0 to 4095)
Dn
V OUT = VREF × ------------ G x
4096
R2
VTRIP = V OUT ⎛ -------------------⎞
⎝ R 1 + R2⎠
FIGURE 7-3:
DS22187E-page 54
Comparator 4
RSENSE
R1
VTRIP4
R2
0.1 µF
Using the MCP4728 for Set Point or Threshold Calibration.
© 2010 Microchip Technology Inc.
MCP4728
ACK (MCP4728)
Start
R/W
UDAC
VREF
GX
S 1 1 0 0 0 0 0 0 A 0 1 0 1 0 0 0 0 A 0 0 0 0 1 0 0 0 A 0 0 0 0 0 0 0 0 A
1st Byte
Device Addressing
for Writing
Dn = 211 = 2048
Sequential Write Selecting
Command
Channel A as
Starting Channel
Update DAC A Input Register at this ACK pulse.
ACK (MCP4728)
VREF
GX
0 0 0 0 1 1 1 1 A 1 1 1 1 1 1 1 1 A
Dn = 4095
Update DAC B Input Register at this ACK pulse.
ACK (MCP4728)
VREF
GX
1 0 0 1 1 0 0 0 A 0 0 0 0 0 0 0 0 A
Dn = 2048
Update DAC C Input Register at this ACK pulse.
ACK (MCP4728)
VREF
Stop
GX
1 0 0 1 1 1 1 1 A 1 1 1 1 1 1 1 1 A P
Dn = 4095
Update DAC D Input Register at this ACK pulse.
Expected Output Voltage at Each Channel:
Dn
VOUT A = V DD × -----------4096
Dn
VOUT B = V DD × -----------4096
Dn
VOUT C = V REF × -----------4096
Dn
V OUT D = VREF × -----------4096
FIGURE 7-4:
2048
= VDD × -----------4096
VDD
= ----------2
4095
= VDD × -----------4096
=
( V)
( V DD – LSB )
(V)
2048
G x = 2.048 × ------------ × 2 = 2.048
4096
(V)
4095
G x = 2.048 × ------------ × 2 = 4.096
4096
(V)
Sequential Write Command for Setting Test Points in Figure 7-3.
© 2010 Microchip Technology Inc.
DS22187E-page 55
MCP4728
Start
1st Byte
2nd Byte
Stop
3rd Byte
S 1 1 0 0 A2 A1 A0 0 A 0 1 1 A2 A1 A0 0 1 A 0 1 1 A2 A1 A0 1 0 A
Address Byte
Fast Mode
Write Command
.......
P
DAC A
Next DAC Channels
The following example shows the expected analog outputs with the corresponding DAC input codes:
DAC A Input Code = 001111-11111111
DAC B Input Code = 000111-11111111
DAC C Input Code = 000011-11111111
DAC D Input Code = 000001-11111111
( V REF × D n )
V OUT = ---------------------------------- G
x
4096
(A) Channel A Output:
Dn for Channel A = 0FFF (hex) = 4095 (decimal)
V OUT A
( V DD × 4095 )
4096 – 1
1
= ------------------------------------ = V DD ⎛ ---------------------⎞ = V DD ⎛ 1 – ------------⎞ = V DD – LSB
⎝ 4096 ⎠
⎝
4096⎠
4096
(B) Channel B Output:
Dn for Channel B = 07FF (hex) = 2047 (decimal)
V OUT B
( V DD × 2047 )
V
V
2048 – 1
DD
2
DD
= ------------------------------------ = V DD ⎛⎝ ---------------------⎞⎠ = ------------- ⎛⎝ 1 – ------------⎞⎠ = ------------- – LSB
4096
4096
2
4096
2
(C) Channel C Output:
Dn for Channel C = 03FF (hex) = 1023 (decimal)
V DD
V DD × 1023
V DD
1024 – 1
4
V OUT C = ---------------------------------- = V DD ⎛⎝ ---------------------⎞⎠ = ------------- ⎛⎝ 1 – ------------⎞⎠ = ------------- – LSB
4096
4096
4
4096
4
(D) Channel D Output:
Dn for Channel D = 01FF (hex) = 511 (decimal)
V DD
V DD
V DD × 511
8
512 – 1
V OUT D = ------------------------------- = V DD ⎛ ------------------⎞ = ------------- ⎛ 1 – ------------⎞ = ------------- – LSB
⎝ 4096 ⎠
4096⎠
8
8 ⎝
4096
FIGURE 7-5:
DS22187E-page 56
Example of Writing Fast Write Command for Various VOUT. VREF = VDD For All Channels.
© 2010 Microchip Technology Inc.
MCP4728
8.0
DEVELOPMENT SUPPORT
8.1
Evaluation & Demonstration
Boards
The MCP4728 Evaluation Board is available from
Microchip Technology Inc. This board works with
Microchip’s PICkit™ Serial Analyzer. The user can
easily program the DAC input registers and EEPROM
using the PICkit Serial Analyzer, and test out the DAC
analog output voltages.The PICkit Serial Analyzer uses
the PC Graphic User Interface software. Refer to
www.microchip.com for further information on this
product’s capabilities and availability.
FIGURE 8-2:
Setup for the MCP4728
Evaluation Board with PICkit™ Serial Analyzer.
FIGURE 8-1:
Board.
MCP4728 Evaluation
FIGURE 8-3:
Example of PICkit™ Serial User Interface.
© 2010 Microchip Technology Inc.
DS22187E-page 57
MCP4728
NOTES:
DS22187E-page 58
© 2010 Microchip Technology Inc.
MCP4728
9.0
PACKAGING INFORMATION
9.1
Package Marking Information
Example
10-Lead MSOP
Device
Code
XXXXXX
MCP4728-E/UN
4728UN
4728UN
YWWNNN
MCP4728T-E/UN
4728UN
007256
MCP4728A0-E/UN
4728A0
MCP4728A0T-E/UN
4728A0
MCP4728A1-E/UN
4728A1
MCP4728A1T-E/UN
4728A1
MCP4728A2-E/UN
4728A2
MCP4728A2T-E/UN
4728A2
MCP4728A3-E/UN
4728A3
MCP4728A3T-E/UN
4728A3
MCP4728A4-E/UN
4728A4
MCP4728A4T-E/UN
4728A4
MCP4728A5-E/UN
4728A5
MCP4728A5T-E/UN
4728A5
MCP4728A6-E/UN
4728A6
MCP4728A6T-E/UN
4728A6
MCP4728A7-E/UN
4728A7
MCP4728A7T-E/UN
4728A7
Legend: XX...X
Y
YY
WW
NNN
e3
*
Note:
Customer-specific information
Year code (last digit of calendar year)
Year code (last 2 digits of calendar year)
Week code (week of January 1 is week ‘01’)
Alphanumeric traceability code
Pb-free JEDEC designator for Matte Tin (Sn)
This package is Pb-free. The Pb-free JEDEC designator ( e3 )
can be found on the outer packaging for this package.
In the event the full Microchip part number cannot be marked on one line, it will
be carried over to the next line, thus limiting the number of available
characters for customer-specific information.
© 2010 Microchip Technology Inc.
DS22187E-page 59
MCP4728
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DS22187E-page 60
© 2010 Microchip Technology Inc.
MCP4728
10-Lead Plastic Micro Small Outline Package (UN) [MSOP]
Note:
For the most current package drawings, please see the Microchip Packaging Specification located at
http://www.microchip.com/packaging
© 2010 Microchip Technology Inc.
DS22187E-page 61
MCP4728
NOTES:
DS22187E-page 62
© 2010 Microchip Technology Inc.
MCP4728
APPENDIX A:
REVISION HISTORY
Revision E (October 2010)
The following is the list of modifications:
1.
2.
3.
Corrected values in I2C Serial Timing
Specifications table (SCL Fall Time, SDA Fall
Time, Data Hold Time, Output Valid from Clock).
Updated the Package Marking Information table
in the “Packaging Information” section.
Updated the information in the section
“Product Identification System”.
Revision D (October 2009)
The following is the list of modifications:
1.
2.
3.
4.
5.
Front page - Applications: Added new item:
Bias Voltage Adjustment for Power Amplifiers.
Electrical Characteristics: Changed typical,
max values for Offset Error.
Electrical Characteristics: Changed Min, Max
values for Gain Error.
Section 2.0 Typical Performance Curves:
Added new Figure 2-25: Absolute Gain Error.
Page 45, Figure 5-15: Changed ACK
(MCP4728) to ACK (MASTER).
Revision C (September 2009)
The following is the list of modifications:
6.
Updated Figure 5-11 and Figure 7-4.
Revision B (August 2009)
The following is the list of modifications:
7.
8.
Updated Figure 2-25 to Figure 2-41 in
Section 2.0 “Typical Performance Curves”.
Updated Figure 5-7, Figure 5-8 and Figure 5-11.
Revision A (June 2009)
• Original Release of this Document.
© 2010 Microchip Technology Inc.
DS22187E-page 63
MCP4728
NOTES:
DS22187E-page 64
© 2010 Microchip Technology Inc.
MCP4728
PRODUCT IDENTIFICATION SYSTEM
To order or obtain information, e.g., on pricing or delivery, refer to the factory or the listed sales office.
PART NO.
XX
Device
Address
Options
Device:
X
/XX
Tape and Temperature
Reel
Range
MCP4728:
Address Options:
-X
XX
Package
12-bit, Quad Digital-to-Analog Convertor with
EEPROM memory
A2
A1
A0
A0 *
=
0
0
0
A1
=
0
0
1
A2
=
0
1
0
A3
=
0
1
1
A4
=
1
0
0
A5
=
1
0
1
A6
=
1
1
0
A7
=
1
1
1
* Default option. Contact Microchip factory for other address
options
Note:
Examples:
a)
b)
c)
d)
e)
f)
g)
h)
These address bits are reprogrammable by the
user.
i)
Tape and Reel:
T
= Tape and Reel
j)
=
-40°C to +125°C
Temperature Range:
E
Package:
UN = Plastic Micro Small Outline Transistor, 10-lead
k)
l)
m)
n)
o)
p)
q)
r)
© 2010 Microchip Technology Inc.
MCP4728-E/UN:
Extended Temperature,
10LD MSOP package.
MCP4728T-E/UN: Tape and Reel,
Extended Temperature,
10LD MSOP package.
MCP4728A0-E/UN: Address Option = A0
Extended Temperature,
10LD MSOP package.
MCP4728A0T-E/UN:Address Option = A0
Tape and Reel,
Extended Temperature,
10LD MSOP package.
MCP4728A1-E/UN: Address Option = A1
Extended Temperature,
10LD MSOP package.
MCP4728A1T-E/UN:Address Option = A1
Tape and Reel,
Extended Temperature,
10LD MSOP package.
MCP4728A2-E/UN: Address Option = A2
Extended Temperature,
10LD MSOP package.
MCP4728A2T-E/UN:Address Option = A2
Tape and Reel,
Extended Temperature,
10LD MSOP package.
MCP4728A3-E/UN: Address Option = A3
Extended Temperature,
10LD MSOP package.
MCP4728A3T-E/UN:Address Option = A3
Tape and Reel,
Extended Temperature,
10LD MSOP package.
MCP4728A4-E/UN: Address Option = A4
Extended Temperature,
10LD MSOP package.
MCP4728A4T-E/UN:Address Option = A4
Tape and Reel,
Extended Temperature,
10LD MSOP package.
MCP4728A5-E/UN: Address Option = A5
Extended Temperature,
10LD MSOP package.
MCP4728A5T-E/UN:Address Option = A5
Tape and Reel,
Extended Temperature,
10LD MSOP package.
MCP4728A6-E/UN: Address Option = A6
Extended Temperature,
10LD MSOP package.
MCP4728A6T-E/UN:Address Option = A6
Tape and Reel,
Extended Temperature,
10LD MSOP package.
MCP4728A7-E/UN: Address Option = A7
Extended Temperature,
10LD MSOP package.
MCP4728A7T-E/UN:Address Option = A7
Tape and Reel,
Extended Temperature,
10LD MSOP package.
DS22187E-page 65
MCP4728
NOTES:
DS22187E-page 66
© 2010 Microchip Technology Inc.
Note the following details of the code protection feature on Microchip devices:
•
Microchip products meet the specification contained in their particular Microchip Data Sheet.
•
Microchip believes that its family of products is one of the most secure families of its kind on the market today, when used in the
intended manner and under normal conditions.
•
There are dishonest and possibly illegal methods used to breach the code protection feature. All of these methods, to our
knowledge, require using the Microchip products in a manner outside the operating specifications contained in Microchip’s Data
Sheets. Most likely, the person doing so is engaged in theft of intellectual property.
•
Microchip is willing to work with the customer who is concerned about the integrity of their code.
•
Neither Microchip nor any other semiconductor manufacturer can guarantee the security of their code. Code protection does not
mean that we are guaranteeing the product as “unbreakable.”
Code protection is constantly evolving. We at Microchip are committed to continuously improving the code protection features of our
products. Attempts to break Microchip’s code protection feature may be a violation of the Digital Millennium Copyright Act. If such acts
allow unauthorized access to your software or other copyrighted work, you may have a right to sue for relief under that Act.
Information contained in this publication regarding device
applications and the like is provided only for your convenience
and may be superseded by updates. It is your responsibility to
ensure that your application meets with your specifications.
MICROCHIP MAKES NO REPRESENTATIONS OR
WARRANTIES OF ANY KIND WHETHER EXPRESS OR
IMPLIED, WRITTEN OR ORAL, STATUTORY OR
OTHERWISE, RELATED TO THE INFORMATION,
INCLUDING BUT NOT LIMITED TO ITS CONDITION,
QUALITY, PERFORMANCE, MERCHANTABILITY OR
FITNESS FOR PURPOSE. Microchip disclaims all liability
arising from this information and its use. Use of Microchip
devices in life support and/or safety applications is entirely at
the buyer’s risk, and the buyer agrees to defend, indemnify and
hold harmless Microchip from any and all damages, claims,
suits, or expenses resulting from such use. No licenses are
conveyed, implicitly or otherwise, under any Microchip
intellectual property rights.
Trademarks
The Microchip name and logo, the Microchip logo, dsPIC,
KEELOQ, KEELOQ logo, MPLAB, PIC, PICmicro, PICSTART,
PIC32 logo, rfPIC and UNI/O are registered trademarks of
Microchip Technology Incorporated in the U.S.A. and other
countries.
FilterLab, Hampshire, HI-TECH C, Linear Active Thermistor,
MXDEV, MXLAB, SEEVAL and The Embedded Control
Solutions Company are registered trademarks of Microchip
Technology Incorporated in the U.S.A.
Analog-for-the-Digital Age, Application Maestro, CodeGuard,
dsPICDEM, dsPICDEM.net, dsPICworks, dsSPEAK, ECAN,
ECONOMONITOR, FanSense, HI-TIDE, In-Circuit Serial
Programming, ICSP, Mindi, MiWi, MPASM, MPLAB Certified
logo, MPLIB, MPLINK, mTouch, Octopus, Omniscient Code
Generation, PICC, PICC-18, PICDEM, PICDEM.net, PICkit,
PICtail, REAL ICE, rfLAB, Select Mode, Total Endurance,
TSHARC, UniWinDriver, WiperLock and ZENA are
trademarks of Microchip Technology Incorporated in the
U.S.A. and other countries.
SQTP is a service mark of Microchip Technology Incorporated
in the U.S.A.
All other trademarks mentioned herein are property of their
respective companies.
© 2010, Microchip Technology Incorporated, Printed in the
U.S.A., All Rights Reserved.
Printed on recycled paper.
ISBN: 978-1-60932-562-6
Microchip received ISO/TS-16949:2002 certification for its worldwide
headquarters, design and wafer fabrication facilities in Chandler and
Tempe, Arizona; Gresham, Oregon and design centers in California
and India. The Company’s quality system processes and procedures
are for its PIC® MCUs and dsPIC® DSCs, KEELOQ® code hopping
devices, Serial EEPROMs, microperipherals, nonvolatile memory and
analog products. In addition, Microchip’s quality system for the design
and manufacture of development systems is ISO 9001:2000 certified.
© 2010 Microchip Technology Inc.
DS22187E-page 67
Worldwide Sales and Service
AMERICAS
ASIA/PACIFIC
ASIA/PACIFIC
EUROPE
Corporate Office
2355 West Chandler Blvd.
Chandler, AZ 85224-6199
Tel: 480-792-7200
Fax: 480-792-7277
Technical Support:
http://support.microchip.com
Web Address:
www.microchip.com
Asia Pacific Office
Suites 3707-14, 37th Floor
Tower 6, The Gateway
Harbour City, Kowloon
Hong Kong
Tel: 852-2401-1200
Fax: 852-2401-3431
India - Bangalore
Tel: 91-80-3090-4444
Fax: 91-80-3090-4123
India - New Delhi
Tel: 91-11-4160-8631
Fax: 91-11-4160-8632
Austria - Wels
Tel: 43-7242-2244-39
Fax: 43-7242-2244-393
Denmark - Copenhagen
Tel: 45-4450-2828
Fax: 45-4485-2829
India - Pune
Tel: 91-20-2566-1512
Fax: 91-20-2566-1513
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Tel: 33-1-69-53-63-20
Fax: 33-1-69-30-90-79
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Tel: 81-45-471- 6166
Fax: 81-45-471-6122
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Tel: 49-89-627-144-0
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Tel: 678-957-9614
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Tel: 630-285-0071
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Mississauga, Ontario,
Canada
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Tel: 86-28-8665-5511
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Fax: 82-53-744-4302
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Tel: 86-23-8980-9588
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Tel: 82-2-554-7200
Fax: 82-2-558-5932 or
82-2-558-5934
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Fax: 63-2-634-9069
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Fax: 65-6334-8850
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Fax: 886-7-330-9305
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Fax: 66-2-694-1350
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Fax: 31-416-690340
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Tel: 34-91-708-08-90
Fax: 34-91-708-08-91
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Tel: 44-118-921-5869
Fax: 44-118-921-5820
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Tel: 86-592-2388138
Fax: 86-592-2388130
China - Zhuhai
Tel: 86-756-3210040
Fax: 86-756-3210049
08/04/10
DS22187E-page 68
© 2010 Microchip Technology Inc.