ETC S9408

SUMMIT
S9408
MICROELECTRONICS, Inc.
Serial Input, Quad 8-Bit Nonvolatile DACPOT™
FEATURES
• Four 8-Bit DACS
– Differential Non-linearity - ±0.5LSB max
– Integral Non-Linearity - ±1LSB max
• Each DAC has Independent Reference Inputs
– Output Buffer Amplifiers Swing Rail-to-Rail
– Ground to VDD Reference Input Range
• Each DAC’s Digital Input Data Maintained in
Nonvolatile EEPROM
• Power-On Reset Reloads Registers with
Nonvolatile Data
• Simple Serial Interface for Reading and Writing
DAC values, SPI™ and QSPI™ compatible.
• Fully operational from 2.7V to 5.5V
OVERVIEW
The S9408 DACPOT™ is a serial input, voltage output,
quad 8-bit digital to analog converter. The S9408 operates from a single +2.7V to +5.5V supply. Internal precision buffers swing rail-to-rail and the reference input
range includes both ground and the positive supply.
The S9408 integrates four 8-bit DACs and their associated circuits which include an enhanced unity-gain operational amplifier output, an 8-bit data latch, an 8-bit nonvolatile register, and an industry-standard serial interface
for reading and writing data to the DACs’ data latches and
registers. The DACs are independently programmable
and each has its own electrically isolated Vreference
inputs.
• Low Power: <1mW @ 2.7V
FUNCTIONAL BLOCK DIAGRAM
Memory Control
8-Bit E2PROM
DAC SECTION 0
VDD
3
RDY/BSY#
4
Serial
Data In
AMP
8-Bit Data Register
CS#
6
DI
7
CLK
5
00/REG#
9
Programming
Memory
Controller
VREFH0
18
VOUT0
11
VREFL0
1
VREFH1
17
VOUT1
12
VREFL1
20
VREFH2
16
VOUT2
13
VREFL2
19
VREFH3
15
VOUT3
14
VREFL3
8
DO
8-Bit DAC
Serial Data Out
DAC SECTION 1
Control
Logic
DAC SECTION 2
GND
2
10
DAC SECTION 3
2015 T BD 2.0
© SUMMIT MICROELECTRONICS, Inc. 2000 • 300 Orchard City Drive, Suite 131 • Campbell, CA 95008 • Phone 408-378-6461 • Fax 408-378-6586 • www.summitmicro.com
Characteristics subject to change without notice
2015 2.2 8/2/00
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S9408
PINOUT and SIGNAL DEFINITION
Pin
20-Pin PDIP
or 20-Pin SOIC
1, 2
VREFH
20, 19
3
VREFH1
VREFH0
VDD
RDY/BSY#
CLK
CS#
DI
DO
00/REG#
GND
1
2
3
4
5
6
7
8
9
10
20
19
18
17
16
15
14
13
12
11
Name
4
VREFH2
VREFH3
VOUT0
VOUT1
VOUT2
VOUT3
VREFL3
VREFL2
VREFL1
VREFL0
2015 T PCon 2.0
The analog outputs of the S9408 can be programmed to
any one of 256 individual voltage steps. Each step value
is 1/256th of the voltage differential between VREFH and
VREFL of the respective DAC. Once programmed these
settings can be retained in nonvolatile memory during all
power conditions and will be automatically recalled upon
a power-up sequence. Each DAC can be independently
read without affecting the output voltage during the read
cycle. In addition, each output can be adjusted an unlimited number of times without altering the value stored in
the nonvolatile memory.
DEVICE OPERATION
Analog Section
The S9804 is an 8-bit, voltage output digital-to-analog
converter (DAC). The DAC consists of a resistor network
that converts 8-bit digital inputs into equivalent analog
output voltages in proportion to the applied reference
voltage.
Reference inputs
The voltage differential between the VREFL and VREFH
inputs sets the full-scale output voltage for its respective
DAC. VREFL must be equal to or greater than ground
(positive voltage). VREFH must be greater (more positive)
than VREFL and less than or equal to VDD.
VDD
Function
Vreference High:
VREFL < VREFH - VDD
Power Supply Voltage
RDY/BSY# Ready/Busy: open drain output
indicating status of nonvolatile
write operations
5
CLK
Clock Input Pin: used for serial
data communication
6
CS#
Chip Select: When high deselects
the device and places it in a low
power mode
7
DI
Data Input: serial data input pin
8
DO
Data Output: serial data output pin
9
00/REG#
Power On Recall Option Input
10
GND
Power Supply Ground
11, 12
13, 14
VREFL
Vreference Low:
VREFH > VREFL • GND
15, 16
17, 18
VOUT
DAC Output: buffered D to A
converter output
Output Buffer Amplifiers
The voltage outputs are precision unity-gain followers that
slew up to 1V/µs. The outputs can swing from VREFL to
VREFH. With a 0V to 5V output transition the amplifier
outputs typically settle to 1LSB in 40µs.
DIGITAL INTERFACE
The S9408 employs a common 4-wire serial interface. It
is comprised of a Clock (CLK), Chip Select (CS#), Data In
(DI) and Data Out (DO). Data is clocked into the device on
the clock’s rising edge and out of the device on the clock’s
falling edge. Data is shifted in and out MSB first. DO only
becomes active after the device has been selected and
after a valid read command and address has been received.
All data transfers are initiated after CS# goes low and a
logic ‘1’ is clocked into the device. This first data transfer
is the start bit and must precede all operations. Following
the start bit are two command bits used to specify which
of four commands to execute. The next two bits are the
address bits used to select one of the four DACs. The
action of the next eight clock cycles will be dependent
upon the command issued.
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S9408
Start
C1
C0
A1
A0
Command
1
0
0
A
A
NV Write Enable
1
0
1
A
A
Write — Data In
1
1
0
A
A
Read — Data Out
1
1
1
A
A
Recall
selected data register. This read will not affect the contents
of the register or the output of the DAC. Refer to Figure 1
for an illustration of the sequence of bus conditions for a
read operation.
TABLE 1. COMMAND FORMAT
Internally there are four DACs and associated with each
are two registers. There is one data register that is used
by the DAC to hold the digital value it converts. There is
also one nonvolatile register that holds the default value
that can be recalled into the data register during powerup or by executing the Recall command.
READ
Read operations are initiated by taking CS# low and
clocking in a start bit followed by the read command and
the address of the data register to be read. The next eight
clocks will output on the DO pin the contents of the
WRITE
Write operations are initiated by taking CS# low and
clocking in a start bit followed by the write command and
the address of the data register to be written. This action
is followed by the host clocking eight bits of data into the
register, MSB first. The output of the selected DAC will
change as the last bit is clocked into the device. At this
point the clock counter will reset the command register,
requiring a full sequence to be initiated in order to write to
the DAC again.
NOTE: This write operation does not affect the
contents of the nonvolatile register. Therefore, the
nonvolatile register can contain the power-on default
settings (e.g. volume), and the write DAC command
can be used to make situational adjustments.
Refer to Figure 2 for an illustration of the sequence of bus
conditions for a write operation.
CS#
CLK
DI
S
T
A
R
T
DO
C1
C0
A1
A0
Hi Z
D7
D6
D5
D4
D3
D2
D1
D0
Hi Z
(Pulled up to VDD)
RDY/BSY#
FIGURE 1. READ SEQUENCE
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2015 T fig01 2.0
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S9408
CS#
CLK
DI
S
T
A
R
T
C1
C0
A1
A0
D7
D6
D5
D4
D3
D2
D1
D0
Hi Z
DO
(Pulled up to VDD)
RDY/BSY#
VOUT
2015 T fig02 2.0
FIGURE 2. WRITE SEQUENCE
Rising Edge Sets
NV Write Enable Latch
Rising Edge Starts
NV Write
CS#
CLK
DI
C1
C0
A1
D0
C1
C0
A1
A0
D7
D6
D5
D4
Address and Data
are Don’t Care
D3
D2
D1
D0
NV Write Enable
Latch is Reset
RDY/BSY#
2015 T fig03 2.0
FIGURE 3. NONVOLATILE WRITE SEQUENCE
NONVOLATILE WRITE
A nonvolatile write is a two step operation: it is initiated by
taking CS# low and clocking in a start bit followed by the
NV Enable command. At this point the host can take CS#
back high or continue clocking in data. This data is don’t
care and will be ignored by the S9408. If any command
other than write follows NV enable the NV latch will be
cleared.
Next, the host takes CS# low again and issues a write
command and address and then clocks in the eight data
bits to be programmed. The host will then bring CS# HIGH
and the data will be latched into the data register and a
nonvolatile write operation will commence.
The status of the nonvolatile write can be monitored on the
RDY/BSY# pin. A logic low indicates the write is still in
progress and the S9408 will not be accessible to the host;
a logic high indicates the write has completed and the
S9408 is ready for the next command. Refer to Figure 3
for an illustration of the sequence of bus conditions for a
nonvolatile write operation.
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SUMMIT MICROELECTRONICS, Inc.
S9408
RECALL COMMAND
The recall command will retrieve data from the selected
nonvolatile register and write it into the data register of the
associated DAC. This operation is initiated by taking CS#
low and clocking in a start bit followed by the recall
command and the address of the nonvolatile register to be
recalled. The eight bits of data are don’t care, so CS# can
be taken high any time after the address bits are clocked
in. Refer to Figure 4 for an illustration of the sequence of
bus conditions for a Recall operation.
Power-on recall
Whenever the S9408 is powered on the DAC output
values will be returned to the selected default setting. The
default setting can be the nonvolatile register contents or
all zeroes. The state of the 00/REG# pin will determine
which operation will be performed. If it is tied to ground (or
left floating) the nonvolatile register contents will be recalled. Conversely, if it is tied to VDD the S9408 will recall
zeroes.
CS#
CLK
DI
S
T
A
R
T
C1
C0
A1
A0
VOUT
2015 T fig04 2.0
FIGURE 4. RECALL COMMAND SEQUENCE
2015 2.2 8/2/00
SUMMIT MICROELECTRONICS, Inc.
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S9408
ABSOLUTE MAXIMUM RATINGS
VDD to GND .................................................................... -0.5V to +7V
Digital Inputs to GND ............................................ -0.5V to VDD+0.5V
Analog Inputs to GND ........................................... -0.5V to VDD+0.5V
Digital Outputs to GND ......................................... -0.5V to VDD+0.5V
Analog Outputs to GND ........................................ -0.5V to VDD+0.5V
Temperature Under Bias ........................................... -55°C to +125°C
Storage Temperature ................................................ -65°C to +150°C
Lead Soldering (10 Sec Max) .................................................... 300°C
RECOMMENDED OPERATING CONDITIONS
Condition
Temperature
VDD
Stresses listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions outside those
listed in the operational sections of this specification is not implied.
Exposure to any absolute maximum rating for extended periods may
affect device performance and reliability.
Min
-40°C
+2.7V
Max
+85°C
+5.5V
2015 PGM T2 1.2
RELIABILITY CHARACTERISTICS (Over recommended operating conditions unless otherwise specified)
Symbol
Parameter
Min
Max
Unit
VZAP
ESD Susceptibility
2000
V
ILTH
Latch-up
100
mA
TDR
Data Retention
100
Years
NEND
Endurance
1,000,000
Storage Cycles
DC ELECTRICAL CHARACTERISTICS (Over recommended operating conditions unless otherwise specified)
Symbol
Parameter
Conditions
Min
Typ
Max
Unit
IDD
Supply current during store
(note 1)
CS = VIL
1.8
23.0
.5
mA
ISB
Standby supply current
CS = VIH
260
500
µA
IIH
Input leakage current
VIN = VDD
<1
10
µA
IIL
Input leakage current
VIN = 0V
<1
–10
µA
VIH
High level input voltage
2
VDD
V
VIL
Low level input voltage
0
0.8
V
VOH
High level output voltage
IOH = –400µA
VOL
Low level output voltage
IOL = 1mA, VDD = 5V;
IOL = 0.4mA, VDD = 2.7V
VDD – 0.3
V
0.4
V
Note 1: IDD is the supply current drawn while the EEPROM is being updated.
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SUMMIT MICROELECTRONICS, Inc.
S9408
AC ELECTRICAL CHARACTERISTICS
VDD = +4.5V to +5.5V, VREFH = VDD, VREFL = 0V, TA = -40°C to +85°C, unless otherwise specified
Symbol
Parameter
fC
Clock Frequency
DC
tWH
Minimum CLK High Time
500
ns
tWL
Minimum CLK Low Time
300
ns
tCS
Minimum CS High Time
150
ns
tCSS
CS Setup Time
100
ns
tCSH
CS Hold Time
0
ns
tSU
Data In Setup Time
CL = 100pF
50
ns
tH
Data In Hold Time
See Note 1
50
ns
tV
Output Valid Time
tHO
Data Out Hold Time
tDIS
Output Disable Time
400
tBUSY
Write Cycle Time
3.3
Notes:
Conditions
Min.
Typ.
Max.
Units
1
MHz
150
ns
0
ns
ns
5
ms
2015 PGM T5 1.1
1. All timing measurements are defined at the point of signal crossing VDD/2.
tCS
CS#
tCSS
tWL
tWH
tCSH
CLK
tSU
tH
DI
tV
Hi Z
tHO
tDIS
Hi Z
DO
RDY/BSY#
2015 T fig05 2.0
FIGURE 5. AC TIMING DIAGRAM
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S9408
DAC DC ELECTRICAL CHARACTERISTICS
VDD = 2.7V to 5.5V, VREFH = VDD, VREFL = 0V, TA = -40°C to +85°C, unless otherwise specified
Property
Accuracy
Symbol
Conditions
Min
Typ
Max
Unit
INL
Integral non-linearity
ILOAD = 100µA
0.5
±1
LSB
DNL
Differential non-linearity
ILOAD = 100µA (note 1)
0.1
±0.5
LSB
VREFH
Input voltage
VREFL
VDD
V
VREFL
Input voltage
GND
VREFh
V
Ω
VREFH to VREFL resistance
40k
TCRIN
Temp. coefficient of RIN
300
600
ppm/ºC
∆RIN
Input resistance match
±0.5
±1
%
±1
LSB
5
mV
50
µV/ºC
1000
µA
References RIN
GEFS
Analog
Output
Parameter
Full-scale gain error
D = FFHEX
VOUTZS Output offset voltage
D = 00HEX
TCVOUT VOUT temp. coeffiecient
VDD = 5V, ILOAD = 50µA
(note 1)
0
2.5
IL
Amp output load current
ROUT
Amp output resistance
ILOAD = 100µA
PSRR
Power supply rejection
ILOAD = 10µA
tS
DAC settling time to 1LSB
10pF
10pF
5V
3V
36
27
eN
Amp output noise
f = 1kHz, VDD = 5V
90
nV√Hz
THD
Total harmonic distortion
VREFH = 2.5V, VDD = 5V,
f = 1kHz, VIN = 1VRMS
0.08
%
BW
Bandwidth –3dB
VREFH = 2.5V, VDD = 5V,
VIN = 100mVRMS
300
kHz
–200
5V
3V
Ω
Ω
10
20
1
LSB/V
40
35
µs
µs
Note 1: Guaranteed but not tested
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SUMMIT MICROELECTRONICS, Inc.
S9408
20 Pin SOIC (.300) Package
0.496 - 0.512
(12.598 - 13.005)
0.394 - 0.419
(10.007 - 10.643)
0.291 - 0.299
(7.391 - 7.595)
0.010 - 0.029
0.093 - 0.104
0.037 - 0.045
(2.362 - 2.642)
x45°
(0.940 - 1.143
(0.254 - 0.737)
0° to 8°
typ
0.009 - 0.013
0.016 - 0.050
0.050
(0.229 - 0.330)
(0.406 - 1.270)
(1.270)
0.004 - 0.012
0.014 - 0.019
(0.102 - 0.305)
(0.356 - 0.482)
20pn SOIC ILL.1
41.5
2015 T fig06 2.0
RESISTANCE (kΩ)
41.0
40.5
40.0
VL = GND
VH = 5.5V
VH = 4.5V
VH = 2.7V
39.5
39.0
–40
25
90
TEMPERATURE (ºC)
FIGURE 6. VL to VH END-TO-END RESISTANCE
OVER TEMPERATURE
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S9408
ORDERING INFORMATION
S9408
Base Part Number
P
Package
P = 20 Pin PDIP *
S = 20 Pin SOIC
* Special order
2015 Tree 2.0
NOTICE
SUMMIT Microelectronics, Inc. reserves the right to make changes to the products contained in this publication in order
to improve design, performance or reliability. SUMMIT Microelectronics, Inc. assumes no responsibility for the use of
any circuits described herein, conveys no license under any patent or other right, and makes no representation that
the circuits are free of patent infringement. Charts and schedules contained herein reflect representative operating
parameters, and may vary depending upon a user’s specific application. While the information in this publication has
been carefully checked, SUMMIT Microelectronics, Inc. shall not be liable for any damages arising as a result of any
error or omission.
SUMMIT Microelectronics, Inc. does not recommend the use of any of its products in life support or aviation applications
where the failure or malfunction of the product can reasonably be expected to cause any failure of either system or to
significantly affect their safety or effectiveness. Products are not authorized for use in such applications unless
SUMMIT Microelectronics, Inc. receives written assurances, to its satisfaction, that: (a) the risk of injury or damage has
been minimized; (b) the user assumes all such risks; and (c) potential liability of SUMMIT Microelectronics, Inc. is
adequately protected under the circumstances.
© Copyright 2000 SUMMIT Microelectronics, Inc.
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SUMMIT MICROELECTRONICS, Inc.