ETC AD5532BBC-1

a
32-Channel, 14-Bit
Voltage-Output DAC
AD5532*
GENERAL DESCRIPTION
FEATURES
High Integration: 32-Channel DAC in 12 mm ⴛ 12 mm
LFBGA
Adjustable Voltage Output Range
Guaranteed Monotonic
Read-Back Capability
DSP/Microcontroller Compatible Serial Interface
Output Impedance
0.5 ⍀ (AD5532-1, AD5532-2)
500 ⍀ (AD5532-3)
1 k⍀ (AD5532-5)
Output Voltage Span
10 V (AD5532-1, AD5532-3, AD5532-5)
20 V (AD5532-2)
Infinite Sample-and-Hold Capability to ⴞ0.018% Accuracy
Temperature Range –40ⴗC to +85ⴗC
The AD5532 is a 32-channel voltage-output 14-bit DAC with
an additional infinite sample-and-hold mode. The selected DAC
register is written to via the 3-wire serial interface and VOUT
for this DAC is then updated to reflect the new contents of the
DAC register. DAC selection is accomplished via Address Bits
A0–A4. The output voltage range is determined by the offset
voltage at the OFFS_IN pin and the gain of the output amplifier.
It is restricted to a range from VSS + 2 V to VDD – 2 V because
of the headroom of the output amplifier.
The device is operated with AVCC = 5 V ± 5%, DVCC = 2.7 V
to 5.25 V, VSS = –4.75 V to –16.5 V and VDD = 8 V to 16.5 V
and requires a stable 3 V reference on REF_IN as well as an
offset voltage on OFFS_IN.
PRODUCT HIGHLIGHTS
1. 32-channel, 14-bit DAC in one package, guaranteed
monotonic.
APPLICATIONS
Automatic Test Equipment
Optical Networks
Level Setting
Instrumentation
Industrial Control Systems
Data Acquisition
Low Cost I/O
2. The AD5532 is available in a 74-lead LFBGA package with
a body size of 12 mm × 12 mm.
3. Droopless/Infinite Sample-and-Hold Mode.
FUNCTIONAL BLOCK DIAGRAM
DVCC
AVCC
REF IN
REF OUT
OFFS IN
VDD
VSS
AD5532
VOUT 0
ADC
TRACK / RESET
BUSY
AGND
DGND
SER /PAR
VOUT 31
MUX
DAC
OFFS OUT
MODE
DAC GND
DAC
14-BIT BUS
VIN
DAC
INTERFACE
CONTROL
LOGIC
SCLK D IN D OUT
ADDRESS INPUT REGISTER
SYNC / CS
A4 –A0
CAL
WR
OFFSET SEL
*Protected by U.S. Patent No. 5,969,657; other patents pending.
REV. B
Information furnished by Analog Devices is believed to be accurate and
reliable. However, no responsibility is assumed by Analog Devices for its
use, nor for any infringements of patents or other rights of third parties that
may result from its use. No license is granted by implication or otherwise
under any patent or patent rights of Analog Devices.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781/329-4700
www.analog.com
Fax: 781/326-8703
© Analog Devices, Inc., 2002
(V = 8 V to 16.5 V, V = –4.75 V to –16.5 V; AV = 4.75 V to 5.25 V; DV = 2.7 V to
AD5532–SPECIFICATIONS
5.25 V; AGND = DGND = DAC_GND = 0 V; REF_IN = 3 V; Output Range from V + 2 V to V – 2 V. All outputs unloaded. All specifications T
DD
SS
SS
CC
CC
DD
MIN
to TMAX, unless otherwise noted.)
Parameter1
A Version2
AD5532-1/-3/-5
AD5532-2 Only
Unit
DAC DC PERFORMANCE
Resolution
Integral Nonlinearity (INL)
Differential Nonlinearity (DNL)
Offset
Gain
Full-Scale Error
14
± 0.39
±1
90/170/250
3.52
±2
14
± 0.39
±1
180/350/500
7
±2
Bits
% of FSR max
LSB max
mV min/typ/max
typ
% of FSR max
3.0
2.85/3.15
1
3.0
2.85/3.15
1
V typ
V min/max
µA max
3
280
60
3
280
60
V typ
kΩ typ
ppm/°C typ
10
10
ppm/°C typ
0.5
500
1
VSS + 2/VDD – 2
5
0.5
Ω typ
Ω typ
kΩ typ
V min/max
kΩ min
VOLTAGE REFERENCE
REF_IN
Nominal Input Voltage
Input Voltage Range3
Input Current
REF_OUT
Output Voltage
Output Impedance3
Reference Temperature Coefficient 3
ANALOG OUTPUTS (VOUT 0–31)
Output Temperature Coefficient 3, 4
DC Output Impedance3
AD5532-1
AD5532-3
AD5532-5
Output Range
Resistive Load3, 5
Capacitive Load3, 5
AD5532-1
AD5532-3
AD5532-5
Short-Circuit Current3
DC Power-Supply Rejection Ratio3
DC Crosstalk3
ANALOG OUTPUT (OFFS_OUT)
Output Temperature Coefficient 3, 4
DC Output Impedance3
Output Range
Output Current
Capacitive Load
DIGITAL INPUTS3
Input Current
Input Low Voltage
Input High Voltage
Input Hysteresis (SCLK and CS Only)
Input Capacitance
DIGITAL OUTPUTS (BUSY, DOUT)3
Output Low Voltage, DVCC = 5 V
Output High Voltage, DVCC = 5 V
Output Low Voltage, DVCC = 3 V
Output High Voltage, DVCC = 3 V
High Impedance Leakage Current
High Impedance Output Capacitance
VSS + 2 /VDD – 2
5
Conditions/Comments
± 0.15% typ
± 0.5 LSB typ, Monotonic
See Figure 6
< 1 nA typ
500
15
40
7
–70
–70
250
500
7
–70
–70
1800
pF max
nF max
nF max
mA typ
dB typ
dB typ
µV max
10
1.3
50 to REF_IN–12
10
100
10
1.3
50 to REF_IN–12
10
100
ppm/°C typ
kΩ typ
mV typ
µA max
pF max
± 10
0.8
0.4
2.4
2.0
200
10
± 10
0.8
0.4
2.4
2.0
200
10
µA max
V max
V max
V min
V min
mV typ
pF max
± 5 µA typ
DVCC = 5 V ±
DVCC = 3 V ±
DVCC = 5 V ±
DVCC = 3 V ±
0.4
4.0
0.4
2.4
±1
15
0.4
4.0
0.4
2.4
±1
15
V max
V min
V max
V min
µA max
pF typ
Sinking 200 µA
Sourcing 200 µA
Sinking 200 µA
Sourcing 200 µA
DOUT Only
DOUT Only
–2–
VDD = +15 V ± 5%
VSS = –15 V ± 5%
Source Current
5%
10%
5%
10%
REV. B
AD5532
A Version2
AD5532-1/-3/-5
AD5532-2 Only
Unit
8/16.5
–4.75/–16.5
4.75/5.25
2.7/5.25
8/16.5
–4.75/–16.5
4.75/5.25
2.7/5.25
V min/max
V min/max
V min/max
V min/max
15
15
mA max
15
15
mA max
33
1.5
280
33
1.5
280
mA max
mA max
mW typ
22
30
µs max
OFFS_IN Settling Time
10
25
µs max
Digital-to-Analog Glitch Impulse
1
1
nV-s typ
Digital Crosstalk
Analog Crosstalk
Digital Feedthrough
Output Noise Spectral Density @ 1 kHz
5
1
0.2
400
5
1
0.2
400
nV-s typ
nV-s typ
nV-s typ
nV/(√Hz) typ
Parameter1
POWER REQUIREMENTS
Power-Supply Voltages
VDD
VSS
AVCC
DVCC
Power-Supply Currents 6
IDD
ISS
AICC
DICC
Power Dissipation6
AC CHARACTERISTICS3
Output Voltage Settling Time
NOTES
1
See Terminology.
2
A Version: Industrial temperature range –40°C to +85°C; typical at +25°C.
3
Guaranteed by design and characterization, not production tested.
Conditions/Comments
10 mA typ.
All Channels Full-Scale
10 mA typ.
All Channels Full-Scale
26 mA typ
1 mA typ
VDD = 10 V, VSS = –5 V
500 pF, 5 kΩ Load
Full-Scale Change
500 pF, 5 kΩ Load;
0 V–3 V Step
1 LSB Change Around
Major Carry
4
AD780 as reference for the AD5532.
Ensure that you do not exceed T J (max). See Maximum Ratings.
6
Output unloaded.
Specifications subject to change without noti ce.
5
ISHA MODE
Parameter1
A Version2
AD5532-1/-3/-5
AD5532-2 Only
Unit
Conditions/Comments
ANALOG CHANNEL
VIN to VOUT Nonlinearity3
± 0.018
± 0.018
% max
± 50
3.46/3.52/3.6
± 75
6.96/7/7.02
mV max
min/typ/max
± 0.006% typ after Offset
and Gain Adjustment
± 10 mV typ. See Figure 7.
See Figure 7
0 to 3
70
0 to 3
70
V
mV max
Input Upper Dead Band
40
40
mV max
Input Current
1
1
µA max
Offset Error
Gain
ANALOG INPUT (VIN)
Input Voltage Range
Input Lower Dead Band
Nominal Input Range
50 mV typ. Referred to VIN.
See Figure 7
12 mV typ. Referred to VIN.
See Figure 7
100 nA typ.
VIN Acquired on 1 Channel
Input Capacitance4
ANALOG INPUT (OFFS_IN)
Input Current
Input Voltage Range
20
20
pF typ
1
0/4
1
0/4
µA max
Vmin/max
100 nA typ
Output Range Restricted
from VSS + 2 V to VDD – 2 V
AC CHARACTERISTICS
Output Settling Time4
Acquisition Time
AC Crosstalk4
3
16
5
3
16
5
µs max
µs max
nV-s typ
Output Unloaded
NOTES
1
See Terminology.
2
A version: Industrial temperature range –40°C to +85°C; typical at +25°C.
Input range 100 mV to 2.96 V.
4
Guaranteed by design and characterization, not production tested.
3
Specifications subject to change without notice.
REV. B
–3–
AD5532
TIMING CHARACTERISTICS
PARALLEL INTERFACE
Parameter1, 2
Limit at TMIN, TMAX
(A Version)
Unit
Conditions/Comments
t1
t2
t3
t4
t5
t6
0
0
50
50
20
7
ns min
ns min
ns min
ns min
ns min
ns min
CS to WR Setup Time
CS to WR Hold Time
CS Pulsewidth Low
WR Pulsewidth Low
A4–A0, CAL, OFFS_SEL to WR Setup Time
A4–A0, CAL, OFFS_SEL to WR Hold Time
NOTES
1
See Interface Timing Diagram.
2
Guaranteed by design and characterization, not production tested.
Specifications subject to change without notice.
SERIAL INTERFACE
Parameter1, 2
fCLKIN3
t1
t2
t3
t4
t5
t6
t7
t8 4
t9 4
t10
t11
t125
Limit at TMIN, TMAX
(A Version)
Unit
Conditions/Comments
14
28
28
15
50
10
5
5
20
60
400
400
7
MHz max
ns min
ns min
ns min
ns min
ns min
ns min
ns min
ns max
ns max
ns min
ns min
ns min
SCLK Frequency
SCLK High Pulsewidth
SCLK Low Pulsewidth
SYNC Falling Edge to SCLK Falling Edge Setup Time
SYNC Low Time
DIN Setup Time
DIN Hold Time
SYNC Falling Edge to SCLK Rising Edge Setup Time for Read Back
SCLK Rising Edge to DOUT Valid
SCLK Falling Edge to DOUT High Impedance
10th SCLK Falling Edge to SYNC Falling Edge for Read Back
24th SCLK Falling Edge to SYNC Falling Edge for DAC Mode Write
SCLK Falling Edge to SYNC Falling Edge Setup Time for Read Back
NOTES
1
See Serial Interface Timing Diagrams.
2
Guaranteed by design and characterization, not production tested.
3
In ISHA mode the maximum SCLK frequency is 20 MHz and the minimum pulsewidth is 20 ns.
4
These numbers are measured with the load circuit of Figure 2.
5
SYNC should be taken low while SCLK is low for read back.
Specifications subject to change without notice.
PARALLEL INTERFACE TIMING DIAGRAMS
CS
200␮A
TO
OUTPUT
PIN
WR
1.6V
CL
50pF
200␮A
A4–A0, CAL,
OFFS SEL
IOL
IOH
Figure 2. Load Circuit for DOUT Timing Specifications
Figure 1. Parallel Write (ISHA Mode Only)
–4–
REV. B
AD5532
SERIAL INTERFACE TIMING DIAGRAMS
t1
SCLK
1
2
3
4
5
6
7
8
9
10
t2
t3
SYNC
t4
t5
t6
DIN
MSB
LSB
Figure 3. 10-Bit Write (ISHA Mode and Both Read-Back Modes)
t1
SCLK
1
2
3
4
21
5
22
23
1
24
t2
t3
SYNC
t4
t 11
t5
t6
DIN
MSB
LSB
Figure 4. 24-Bit Write (DAC Mode)
t1
t7
SCLK
1
10
2
t12
3
4
5
6
7
8
9
10
11
12
13
14
t2
SYNC
t10
t4
t8
t9
DOUT
MSB
LSB
Figure 5. 14-Bit Read (Both Read-Back Modes)
REV. B
–5–
AD5532
ABSOLUTE MAXIMUM RATINGS 1, 2
Reflow Soldering
Peak Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . 220°C
Time at Peak Temperature . . . . . . . . . . . . 10 sec to 40 sec
Max Power Dissipation . . . . . . . . . . . . (150°C – TA)/θJA mW3
Max Continuous Load Current at TJ = 70°C,
per Channel Group . . . . . . . . . . . . . . . . . . . . . . . . . 15 mA4
(TA = 25°C unless otherwise noted.)
VDD to AGND . . . . . . . . . . . . . . . . . . . . . . . . –0.3 V to +17 V
VSS to AGND . . . . . . . . . . . . . . . . . . . . . . . . +0.3 V to –17 V
AVCC to AGND, DAC_GND . . . . . . . . . . . . . –0.3 V to +7 V
DVCC to DGND . . . . . . . . . . . . . . . . . . . . . . . –0.3 V to +7 V
Digital Inputs to DGND . . . . . . . . . . –0.3 V to DVCC + 0.3 V
Digital Outputs to DGND . . . . . . . . . –0.3 V to DVCC + 0.3 V
REF_IN to AGND, DAC_ GND . . . –0.3 V to AVCC + 0.3 V
VIN to AGND, DAC_GND . . . . . . . . –0.3 V to AVCC + 0.3 V
VOUT 0–31 to AGND . . . . . . . . . . VSS – 0.3 V to VDD + 0.3 V
OFFS_IN to AGND . . . . . . . . . . VSS – 0.3 V to VDD + 0.3 V
OFFS_OUT to AGND . . . . AGND – 0.3 V to AVCC + 0.3 V
AGND to DGND . . . . . . . . . . . . . . . . . . . . –0.3 V to +0.3 V
Operating Temperature Range
Industrial . . . . . . . . . . . . . . . . . . . . . . . . . . –40°C to +85°C
Storage Temperature Range . . . . . . . . . . . . –65°C to +150°C
Junction Temperature (TJ max) . . . . . . . . . . . . . . . . . . 150°C
74-Lead LFBGA Package, θJA Thermal Impedance . . . 41°C/W
NOTES
1
Stresses above those listed under Absolute Maximum Ratings may cause permanent damage to the device. This is a stress rating only; functional operation of the
device at these or any other conditions above those listed in the operational
sections of this specification is not implied. Exposure to absolute maximum rating
conditions for extended periods may affect device reliability.
2
Transient currents of up to 100 mA will not cause SCR latch-up.
3
This limit includes load power.
4
This maximum allowed continuous load current is spread over 8 channels and
channels are grouped as follows:
Group 1: Channels 3, 4, 5, 6, 7, 8, 9, 10
Group 2: Channels 14, 16, 18, 20. 21, 24, 25, 26
Group 3: Channels 15, 17, 19, 22, 23, 27, 28, 29
Group 4: Channels 0, 1, 2, 11, 12, 13, 30, 31
For higher junction temperatures derate as follows:
TJ (°C)
Max Continuous Load Current
per Group (mA)
70
90
100
110
125
135
150
15.5
9.025
6.925
5.175
3.425
2.55
1.5
ORDERING GUIDE
Output
Impedance
Model
Function
AD5532ABC-1
AD5532ABC-2
AD5532ABC-3
AD5532ABC-5
AD5532BBC-1*
AD5533ABC-1*
AD5533BBC-1*
AD5532HS*
EVAL-AD5532EB
32 DACs, 32-Channel ISHA
0.5 kΩ typ
32 DACs, 32-Channel ISHA
0.5 kΩ typ
32 DACs, 32-Channel ISHA
500 kΩ typ
32 DACs, 32-Channel ISHA
1 kΩ typ
32 DACs, 32-Channel Precision ISHA 0.5 kΩ typ
32-Channel ISHA Only
0.5 kΩ typ
32-Channel Precision ISHA Only
0.5 kΩ typ
32-Channel High Speed DAC
0.5 kΩ typ
Evaluation Board
Output
Voltage Span
Package
Description
Package
Option
10 V
20 V
10 V
10 V
10 V
10 V
10 V
5V
74-Lead LFBGA
74-Lead LFBGA
74-Lead LFBGA
74-Lead LFBGA
74-Lead LFBGA
74-Lead LFBGA
74-Lead LFBGA
74-Lead LFBGA
BC-74
BC-74
BC-74
BC-74
BC-74
BC-74
BC-74
BC-74
*Separate Data Sheet
CAUTION
ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readily
accumulate on the human body and test equipment and can discharge without detection. Although
the AD5532 features proprietary ESD protection circuitry, permanent damage may occur on
devices subjected to high energy electrostatic discharges. Therefore, proper ESD precautions are
recommended to avoid performance degradation or loss of functionality.
–6–
WARNING!
ESD SENSITIVE DEVICE
REV. B
AD5532
PIN CONFIGURATION
1
2
3
4
5
6
7
8
9
10 11
A
A
B
B
C
C
D
D
E
E
TOP VIEW
F
F
G
G
H
H
J
J
K
K
L
L
1
2
3
4
5
6
7
8
9
10 11
74-Lead LFBGA Ball Configuration
LFBGA
Number
Ball
Name
LFBGA
Number
Ball
Name
LFBGA
Number
Ball
Name
A1
A2
A3
A4
A5
A6
A7
A8
A9
A10
A11
B1
B2
B3
B4
B5
B6
B7
B8
B9
B10
B11
C1
C2
C6
N/C*
A4
A2
A0
CS/SYNC
DVCC
SCLK
OFFSET_SEL
BUSY
TRACK/RESET
N/C*
VO16
N/C*
A3
A1
WR
DGND
DIN
CAL
SER/PAR
DOUT
REF_IN
VO18
DAC_GND1
N/C*
C10
C11
D1
D2
D10
D11
E1
E2
E10
E11
F1
F2
F10
F11
G1
G2
G10
G11
H1
H2
H10
H11
J1
J2
J6
AVCC1
REF_OUT
VO20
DAC_GND2
AVCC2
OFFS_OUT
VO26
VO14
AGND1
OFFS_IN
VO25
VO21
AGND2
VO6
VO24
VO8
VO5
VO3
VO23
VIN
VO4
VO7
VO22
VO19
VSS2
J10
J11
K1
K2
K3
K4
K5
K6
K7
K8
K9
K10
K11
L1
L2
L3
L4
L5
L6
L7
L8
L9
L10
L11
VO9
VO11
VO17
VO15
VO27
VSS3
VSS1
VSS4
VDD2
VO2
VO10
VO13
VO12
N/C*
VO28
VO29
VO30
VDD3
VDD1
VDD4
VO31
VO0
VO1
N/C*
*N/C = Not Connected
REV. B
–7–
AD5532
PIN FUNCTION DESCRIPTION
Pin
Function
AGND (1–2)
AVCC (1–2)
VDD (1–4)
VSS (1–4)
DGND
DVCC
DAC_GND (1–2)
REF_IN
REF_OUT
VOUT (0–31)
VIN
A4–A11, A02
CAL1
CS/SYNC
Analog GND Pins
Analog Supply Pins. Voltage range from 4.75 V to 5.25 V.
VDD Supply Pins. Voltage range from 8 V to 16.5 V.
VSS Supply Pins. Voltage range from –4.75 V to –16.5 V.
Digital GND Pins
Digital Supply Pins. Voltage range from 2.7 V to 5.25 V.
Reference GND Supply for All the DACs
Reference Voltage for Channels 0–31
Reference Output Voltage
Analog Output Voltages from the 32 Channels
Analog Input Voltage. Connect this to AGND if operating in DAC mode only.
Parallel Interface: 5-Address Pins for 32 Channels. A4 = MSB of Channel Address. A0 = LSB.
Parallel Interface: Control input that allows all 32 channels to acquire VIN simultaneously.
This pin is both the active low Chip Select pin for the parallel interface and the Frame Synchronization pin
for the serial interface.
Parallel Interface: Write pin. Active low. This is used in conjunction with the CS pin to address the device
using the parallel interface.
Parallel Interface: Offset Select pin. Active high. This is used to select the offset channel.
Serial Clock Input for Serial Interface. This operates at clock speeds up to 14 MHz (20 MHz in ISHA mode).
Data Input for Serial Interface. Data must be valid on the falling edge of SCLK.
Output from the DAC Registers for read back. Data is clocked out on the rising edge of SCLK and is
valid on the falling edge of SCLK.
This pin allows the user to select whether the serial or parallel interface will be used. If the pin is tied low,
the parallel interface will be used. If it is tied high, the serial interface will be used.
Offset Input. The user can supply a voltage here to offset the output span. OFFS_OUT can also be tied to
this pin if the user wants to drive this pin with the Offset Channel.
Offset Output. This is the acquired/programmed offset voltage which can be tied to OFFS_IN to offset the
span.
This output tells the user when the input voltage is being acquired. It goes low during acquisition and
returns high when the acquisition operation is complete.
If this input is held high, VIN is acquired once the channel is addressed. While it is held low, the input to the
gain/offset stage is switched directly to VIN. The addressed channel begins to acquire VIN on the rising edge
of TRACK. See TRACK Input section for further information. This input can also be used as a means of
resetting the complete device to its power-on-reset conditions. This is achieved by applying a low-going
pulse of between 90 ns and 200 ns to this pin. See section on RESET Function for further details.
WR1
OFFSET_SEL1
SCLK2
DIN2
DOUT
SER/PAR1
OFFS_IN
OFFS_OUT
BUSY
TRACK/RESET2
NOTES
1
Internal pull-down devices on these logic inputs. Therefore, they can be left floating and will default to a logic low condition.
2
Internal pull-up devices on these logic inputs. Therefore, they can be left floating and will default to a logic high condition.
VOUT
OUTPUT
VOLTAGE
FULL-SCALE
ERROR RANGE
IDEAL GAIN ⴛ REFIN
IDEAL TRANSFER
FUNCTION
OFFSET
RANGE
GAIN ERROR +
OFFSET ERROR
IDEAL
TRANSFER
FUNCTION
OFFSET
ERROR
ACTUAL
TRANSFER
FUNCTION
IDEAL GAIN ⴛ 50mV
0
0V
16k
DAC CODE
70mV
LOWER
DEAD BAND
2.96 3V
VIN
UPPER
DEAD BAND
Figure 7. ISHA Transfer Function
Figure 6. DAC Transfer Function (OFFS_IN = 0)
–8–
REV. B
AD5532
TERMINOLOGY
Output Noise Spectral Density
DAC MODE
Integral Nonlinearity (INL)
This is a measure of internally generated random noise. Random
noise is characterized as a spectral density (voltage per root Hertz).
It is measured by loading all DACs to midscale and measuring noise at the output. It is measured in nV/(√Hz).
This is a measure of the maximum deviation from a straight line
passing through the endpoints of the DAC transfer function. It
is expressed as a percentage of full-scale span.
Differential Nonlinearity (DNL)
Differential nonlinearity (DNL) is the difference between the
measured change and the ideal 1 LSB change between any two
adjacent codes. A specified DNL of ± 1 LSB maximum ensures
monotonicity.
Offset
Offset is a measure of the output with all zeros loaded to the
DAC and OFFS_IN = 0. Since the DAC is lifted off the ground
by approximately 50 mV, this output will typically be:
Output Temperature Coefficient
This is a measure of the change in analog output with changes
in temperature. It is expressed in ppm/°C.
DC Power-Supply Rejection Ratio
DC power-supply rejection ratio (PSRR) is a measure of the
change in analog output for a change in supply voltage (VDD and
VSS). It is expressed in dBs. VDD and VSS are varied ± 5%.
DC Crosstalk
Full-Scale Error
This is the DC change in the output level of one DAC at
midscale in response to a full-scale code change (all 0s to all 1s
and vice versa) and output change of all other DACs. It is expressed in µV.
This is a measure of the output error with all 1s loaded to the
DAC. It is expressed as a percentage of full-scale range. See Figure
6. It is calculated as:
ISHA MODE
VIN to VOUT Nonlinearity
VOUT = Gain × 50 mV
Full-Scale Error = VOUT(Full-Scale) – (Ideal Gain × REFIN)
where
Ideal Gain = 3.52 for AD5532-1/-3/-5
Ideal Gain = 7 for AD5532-2
Output Settling Time
This is the time taken from when the last data bit is clocked into
the DAC until the output has settled to within ±0.39%.
OFFS_IN Settling Time
This is the time taken from a 0 V–3 V step change in input voltage on OFFS_IN until the output has settled to within ±0.39%.
Digital-to-Analog Glitch Impulse
This is the area of the glitch injected into the analog output when
the code in the DAC register changes state. It is specified as the
area of the glitch in nV-secs when the digital code is changed by
1 LSB at the major carry transition (011 . . . 11 to 100 . . . 00 or
100 . . . 00 to 011 . . . 11).
This is a measure of the maximum deviation from a straight line
passing through the endpoints of the VIN versus VOUT transfer
function. It is expressed as a percentage of the full-scale span.
Offset Error
This is a measure of the output error when VIN = 70 mV. Ideally,
with VIN = 70 mV:
VOUT = (Gain × 70) – ((Gain – 1) × VOFFS_IN) mV
Offset error is a measure of the difference between VOUT (actual)
and VOUT (ideal). It is expressed in mV and can be positive or
negative. See Figure 7.
Gain Error
This is a measure of the span error of the analog channel. It is
the deviation in slope of the transfer function expressed in mV.
See Figure 7. It is calculated as:
Gain Error = Actual Full-Scale Output – Ideal Full-Scale Output –
Offset Error
where
Digital Crosstalk
This is the glitch impulse transferred to the output of one DAC
at midscale while a full-scale code change (all 1s to all 0s and vice
versa) is being written to another DAC. It is expressed in nV-secs.
Analog Crosstalk
This is the area of the glitch transferred to the output (VOUT)
of one DAC due to a full-scale change in the output (VOUT)
of another DAC. The area of the glitch is expressed in nV-secs.
Digital Feedthrough
This is a measure of the impulse injected into the analog outputs
from the digital control inputs when the part is not being written
to, i.e., CS/SYNC is high. It is specified in nV-secs and is measured with a worst-case change on the digital input pins, e.g.,
from all 0s to all 1s and vice versa.
REV. B
Ideal Full-Scale Output = Gain × 2.96 – ((Gain – 1) × VOFFS_IN)
AC Crosstalk
This is the area of the glitch that occurs on the output of one
channel while another channel is acquiring. It is expressed in
nV-secs.
Output Settling Time
This is the time taken from when BUSY goes high to when the
output has settled to ± 0.018%.
Acquisition Time
This is the time taken for the VIN input to be acquired. It is the
length of time that BUSY stays low.
–9–
AD5532 –Typical Performance Characteristics
0.2
DNL ERROR – LSBs
0.4
0.2
0.0
–0.2
–0.4
5.315
DNL MAX
0.5
0.1
INL MAX
0.0
0.0
INL MIN
–0.5
–0.1
DNL MIN
–0.6
5.325
VOUT – V
TA = 25ⴗC
0.6
DNL ERROR – LSBs
1.0
VREFIN = 3V
VOFFS_IN = 0V
0.8
INL ERROR – % FSR
1.0
DAC LOADED TO MIDSCALE
VREFIN = 3V
VOFFS_IN = 0V
5.305
5.295
5.285
–0.8
–1.0
0
2k
4k
TPC 1. Typical DNL Plot
–0.2
–1.0
–40
6k 8k 10k 12k 14k 16k
DAC CODE
0
40
TEMPERATURE – ⴗC
5.275
–40
80
TPC 2. INL Error and DNL Error vs.
Temperature
TA = 25ⴗC
VREFIN = 3V
8.0
5.309
TA = 25ⴗC
VREFIN = 3V
VOFFS_IN = 0.5V
5.308
5.307
VOUT – V
VOUT – V
VOUT – V
6.0
3.530
4.0
5.306
5.305
5.304
2.0
3.525
5.303
0.0
4
2
–2
–4
0
SINK/SOURCE CURRENT – mA
0.024
0.020
0.016
TA = 25ⴗC
VREFIN = 3V
VOFFS_IN = 0V
5.301
–2.0
6
–6
TPC 4. VOUT Source and Sink
Capability
TIME BASE – 2␮s/DIV
TIME BASE – 50ns/DIV
TPC 5. Full-Scale Settling Time
TPC 6. Major Code Transition
Glitch Impulse
70k
TA = 25ⴗC
VREFIN = 3V
VOFFS_IN = 0V
63791
60k
5V
0.012
VOUT ERROR – %
5.302
100
0.004
VOUT
0.000
–0.004
TA = 25ⴗC
VREFIN = 3V
VIN = 0 1.5V
–0.008
10
–0.012
50k
BUSY
90
0.008
FREQUENCY
3.520
80
TPC 3. VOUT vs. Temperature
10.0
3.535
0
40
TEMPERATURE – ⴗC
TA = 25ⴗC
VREFIN = 3V
VIN = 1.5V
VOFFS_IN = 0V
40k
30k
20k
0%
–0.016
1V
–0.020
–0.024
0.1
2␮s
10k
0
VIN – V
TPC 7. VIN to VOUT Accuracy
After Offset and Gain Adjustment
(ISHA Mode)
2.96
TPC 8. Acquisition Time and
Output Settling Time (ISHA Mode)
–10–
1545
200
5.2670
5.2676
VOUT – V
5.2682
TPC 9. ISHA-Mode Repeatability
(64 K Acquisitions)
REV. B
AD5532
place. If the applied pulse is wider than 200 ns, this pin adopts
its track function on the selected channel, VIN is switched to the
output buffer, and an acquisition on the channel will not occur
until a rising edge of TRACK.
FUNCTIONAL DESCRIPTION
The AD5532 can be thought of as consisting of 32 DACs and
an ADC (for ISHA Mode) in a single package. In DAC Mode,
a 14-bit digital word is loaded into one of the 32 DAC Registers
via the serial interface. This is then converted (with gain and
offset) into an analog output voltage (VOUT0–VOUT31).
ISHA Mode
To update a DAC’s output voltage, the required DAC is addressed
via the serial port. When the DAC address and code have been
loaded, the selected DAC converts the code.
On power-on, all the DACs, including the offset channel, are
loaded with zeros. Each of the 33 DACs is offset internally by
50 mV (typ) from GND, so the outputs VOUT 0 to VOUT 31 are
50 mV (typ) on power-on if the OFFS_IN pin is driven directly by
the on-board offset channel (OFFS_OUT), i.e. if OFFS_IN is
50 mV, VOUT = (Gain × VDAC) – (Gain – 1) × VOFFS_IN = 50 mV.
Output Buffer Stage—Gain and Offset
The function of the output buffer stage is to translate the 50 mV–3 V
output of the DAC to a wider range. This is done by gaining up
the DAC output by 3.52/7 and offsetting the voltage by the
voltage on OFFS_IN pin.
AD5532-1/AD5532-3/AD5532-5:
VOUT = 3.52 × VDAC – 2.52 × VOFFS_IN
AD5532-2:
VOUT = 7 × VDAC – 6 × VOFFS_IN
VDAC is the output of the DAC.
VOFFS_IN is the voltage at the OFFS_IN pin.
The following table shows how the output range on VOUT relates
to the offset voltage supplied by the user.
In ISHA Mode, the input voltage VIN is sampled and converted
into a digital word. The noninverting input to the output buffer
(gain and offset stage) is tied to VIN during the acquisition period
to avoid spurious outputs, while the DAC acquires the correct
code. This is completed in 16 µs max. At this time the updated
DAC output assumes control of the output voltage. The output
voltage of the DAC is connected to the noninverting input of
the output buffer. Since the channel output voltage is effectively
the output of a DAC, there is no droop associated with it. As
long as power is maintained to the device, the output voltage will
remain constant until this channel is addressed again. Since the
internal DACs are offset by 70 mV (max) from GND, the minimum VIN in ISHA Mode is 70 mV. The maximum VIN is 2.96 V
due to the upper dead band of 40 mV (max).
Analog Input (ISHA Mode)
The equivalent analog input circuit is shown in Figure 8. The
Capacitor C1 is typically 20 pF and can be attributed to pin
capacitance and 32 off-channels. When a channel is selected, an
extra 7.5 pF (typ) is switched in. This Capacitor C2 is charged
to the previously acquired voltage on that particular channel
so it must charge/discharge to the new level. It is essential that the
external source can charge/discharge this additional capacitance within 1 µs–2 µs of channel selection so that VIN can be
acquired accurately. For this reason, a low impedance source
is recommended.
ADDRESSED CHANNEL
Table I. Sample Output Voltage Ranges
VIN
VOFFS_IN
(V)
VDAC
(V)
VOUT
(AD5532-1/-3/-5)
0.5
1
0.05 to 3 –1.26 to +9.3
0.05 to 3 –2.52 to +8.04
C2
7.5pF
Headroom Limited
–6 to +15
VOUT is limited only by the headroom of the output amplifiers.
VOUT must be within maximum ratings.
Offset Voltage Channel
The offset voltage can be externally supplied by the user at
OFFS_IN or it can be supplied by an additional offset voltage
channel on the device itself. The offset can be set up in two
ways. In ISHA Mode, the required offset voltage is set up on
VIN and acquired by the offset channel. In DAC Mode, the
code corresponding to the offset value is loaded directly into
the offset DAC. This offset channel’s DAC output is directly
connected to OFFS_OUT. By connecting OFFS_OUT to OFFS_IN
this offset voltage can be used as the offset voltage for the 32
output amplifiers. It is important to choose the offset so that
VOUT is within maximum ratings.
Reset Function
The reset function on the AD5532 can be used to reset all nodes
on this device to their power-on-reset condition. This is implemented by applying a low-going pulse of between 90 ns and 200 ns
to the TRACK/RESET pin on the device. If the applied pulse is
less than 90 ns, it is assumed to be a glitch and no operation takes
REV. B
C1
20pF
VOUT
(AD5532-2)
Figure 8. Analog Input Circuit
Large source impedances will significantly affect the performance
of the ADC. This may necessitate the use of an input buffer
amplifier.
TRACK Function (ISHA Mode)
Normally in ISHA Mode of operation TRACK is held high and
the channel begins to acquire when it is addressed. However, if
TRACK is low when the channel is addressed, VIN is switched to
the output buffer and an acquisition on the channel will not
occur until a rising edge of TRACK. At this stage, the BUSY pin
will go low until the acquisition is complete, at which point the
DAC assumes control of the voltage to the output buffer and
VIN is free to change again without affecting this output value.
This is useful in an application where the user wants to ramp up
VIN until VOUT reaches a particular level (Figure 9). VIN does not
need to be acquired continuously while it is ramping up. TRACK
–11–
AD5532
PIN
DRIVER
CONTROLLER
DAC
VIN
OUTPUT
STAGE
ACQUISITION
CIRCUIT
VOUT1
DEVICE
UNDER
TEST
BUSY
AD5532
TRACK
THRESHOLD
VOLTAGE
ONLY ONE CHANNEL SHOWN FOR SIMPLICITY
Figure 9. Typical ATE Circuit Using TRACK Input
can be kept low and only when VOUT has reached its desired voltage
is TRACK brought high. At this stage, the acquisition of VIN begins.
In the example shown, a desired voltage is required on the output of the pin driver. This voltage is represented by one input to
a comparator. The microcontroller/microprocessor ramps up
the input voltage on VIN through a DAC. TRACK is kept low
while the voltage on VIN ramps up so that VIN is not continually acquired. When the desired voltage is reached on the output
of the pin driver, the comparator output switches. The µC/µP
then knows what code is required to be input to obtain the
desired voltage at the DUT. The TRACK input is now brought
high and the part begins to acquire VIN. At this stage BUSY
goes low until VIN has been acquired. The output buffer is then
switched from VIN to the output of the DAC.
on the next falling edge of SYNC, the data in the relevant DAC
register is clocked out onto the DOUT line in a 14-bit serial format.
The user must allow 400 ns (min) between the last SCLK falling edge in the 10-bit write and the falling edge of SYNC in
the 14-bit read back. The serial write and read words can be
seen in Figure 10.
This feature allows the user to read back the DAC register code
of any of the channels. In DAC Mode, this is useful in verification of
write cycles. In ISHA Mode, read back is useful if the system
has been calibrated and the user wants to know what code in
the DAC corresponds to a desired voltage on VOUT. If the user
requires this voltage again, he can input the code directly to the
DAC register without going through the acquisition sequence.
MODES OF OPERATION
INTERFACES
Serial Interface
The AD5532 can be used in four different modes of operation. These modes are set by two mode bits, the first two bits in
the serial word.
The SER/PAR pin is tied high to enable the serial interface and
to disable the parallel interface. The serial interface is controlled
by the four pins that follow.
SYNC, DIN, SCLK
Table II. Modes of Operation
Mode Bit 1
Mode Bit 2
Operating Mode
0
0
1
1
0
1
0
1
ISHA Mode
DAC Mode
Acquire and Read Back
Read Back
Standard 3-wire interface pins. The SYNC pin is shared with
the CS function of the parallel interface.
DOUT
Data Out pin for reading back the contents of the DAC registers. The data is clocked out on the rising edge of SCLK and
is valid on the falling edge of SCLK.
1. ISHA Mode
Mode Bits
In this mode, a channel is addressed and that channel acquires
the voltage on VIN. This mode requires a 10-bit write (see
Figure 10a) to address the relevant channel (VOUT0–VOUT31, offset
channel or all channels) MSB is written first.
There are four different modes of operation as described above.
Cal Bit
In DAC Mode, this is a test bit. When it is high, it is used to load
all zeros or all ones to the 32 DACs simultaneously. In ISHA Mode,
all 32 channels acquire VIN simultaneously when this bit is high.
In ISHA Mode, the acquisition time is then 45 µs (typ) and accuracy may be reduced. This bit is set low for normal operation.
2. DAC Mode
In this standard mode, a selected DAC register is loaded serially.
This requires a 24-bit write (10 bits to address the relevant DAC
plus an extra 14 bits of DAC data). MSB is written first. The
user must allow 400 ns (min) between successive writes in
DAC Mode.
Offset_Sel Bit
If this is set high, the offset channel is selected and Bits A4–
A0 are ignored.
3. Acquire and Read-Back Mode
Test Bit
This mode allows the user to acquire VIN and read back the data
in a particular DAC register. The relevant channel is addressed
(10-bit write, MSB first) and VIN is acquired in 16 µs (max).
Following the acquisition, after the next falling edge of SYNC,
the data in the relevant DAC register is clocked out onto the
DOUT line in a 14-bit serial format. The full acquisition time
must elapse before the DAC register data can be clocked out.
This must be set low for correct operation of the part.
4. Read Back Mode
A4–A0
Used to address any one of the 32 channels (A4 = MSB of
address, A0 = LSB).
DB13–DB0
These are used to write a 14-bit word into the addressed DAC
register. Clearly, this is only valid when in DAC Mode.
Again, this is a Read-Back Mode but no acquisition is performed.
The relevant channel is addressed (10-bit write, MSB first) and
–12–
REV. B
AD5532
MSB
LSB
0
0
MODE BIT 1
CAL
0
OFFSET SEL
MODE BIT 2
A4 –A0
TEST BIT
MODE BITS
a. 10-Bit Input Serial Write Word (ISHA Mode)
MSB
LSB
0
1
CAL
0
OFFSET SEL
A4 –A0
DB1 3 –DB0
TEST BIT
MODE BITS
b. 24-Bit Input Serial Write Word (DAC Mode)
LSB
MSB
1
0
CAL
OFFSET SEL
MSB
A4 –A0
0
LSB
DB1 3 –DB0
TEST BIT
MODE BITS
14-BIT DATA
READ FROM PART AFTER
NEXT FALLING EDGE OF SYNC
(DB13 = MSB OF DAC WORD)
10-BIT
SERIAL WORD
WRITTEN TO PART
c. Input Serial Interface (Acquire and Read-Back Mode)
LSB
MSB
1
1
CAL
OFFSET SEL
MSB
A4 –A0
0
LSB
DB1 3 –DB0
TEST BIT
MODE BITS
14-BIT DATA
READ FROM PART AFTER
NEXT FALLING EDGE OF SYNC
(DB13 = MSB OF DAC WORD)
10-BIT
SERIAL WORD
WRITTEN TO PART
d. Input Serial Interface (Read-Back Mode)
Figure 10. Serial Interface Formats
The serial interface is designed to allow easy interfacing to
most microcontrollers and DSPs, e.g., PIC16C, PIC17C, QSPI,
SPI, DSP56000, TMS320, and ADSP-21xx, without the need
for any glue logic. When interfacing to the 8051, the SCLK
must be inverted. The Microprocessor Interfacing section explains
how to interface to some popular DSPs and microcontrollers.
Parallel Interface (ISHA Mode Only)
The SER/PAR Bit must be tied low to enable the parallel interface and disable the serial interface. The parallel interface is
controlled by nine pins, which follow:
CS
Active low package select pin. This pin is shared with the SYNC
function for the serial interface.
Figures 3, 4, and 5 show the timing diagram for a serial read and
write to the AD5532. The serial interface works with both a continuous and a noncontinuous serial clock. The first falling edge of
SYNC resets a counter that counts the number of serial clocks to
ensure the correct number of bits are shifted in and out of the
serial shift registers. Any further edges on SYNC are ignored until
the correct number of bits are shifted in or out. Once the correct
number of bits for the selected mode have been shifted in or out,
the SCLK is ignored. In order for another serial transfer to take
place the counter must be reset by the falling edge of SYNC.
WR
Active low write pin. The values on the address pins are latched
on a rising edge of WR.
A4–A0
Five address pins (A4 = MSB of address, A0 = LSB). These
are used to address the relevant channel (out of a possible 32).
OFFSET_SEL
Offset select pin. This has the same function as the Offset_Sel
bit in the serial interface. When it is high, the offset channel
is addressed. The address on A4–A0 is ignored in this case.
In read back, the first rising SCLK edge after the falling edge of
SYNC causes DOUT to leave its high impedance state and data
is clocked out onto the DOUT line and also on subsequent SCLK
rising edges. The DOUT pin goes back into a high impedance
state on the falling edge of the fourteenth SCLK. Data on the
DIN line is latched in on the first SCLK falling edge after the
falling edge of the SYNC signal and on subsequent SCLK falling edges. During read-back DIN is ignored. The serial interface
will not shift data in or out until it receives the falling edge of
the SYNC signal.
REV. B
CAL
When this pin is high, all 32 channels acquire VIN simultaneously. The acquisition time is then 45 µs (typ) and accuracy
may be reduced.
–13–
AD5532
MICROPROCESSOR INTERFACING
AD5532 to ADSP-21xx Interface
The ADSP-21xx family of DSPs are easily interfaced to the
AD5532 without the need for extra logic.
A data transfer is initiated by writing a word to the TX Register
after the SPORT has been enabled. In a write sequence, data is
clocked out on each rising edge of the DSP’s serial clock and
clocked into the AD5532 on the falling edge of its SCLK. In
read back, 16 bits of data are clocked out of the AD5532 on each
rising edge of SCLK and clocked into the DSP on the rising
edge of SCLK. DIN is ignored. The valid 14 bits of data will be
centered in the 16-bit RX Register when using this configuration.
The SPORT Control Register should be set up as follows:
TFSW
INVRFS
DTYPE
ISCLK
TFSR
IRFS
ITFS
SLEN
SLEN
SLEN
MC68HC11*
AD5532*
= RFSW = 1, Alternate Framing
= INVTFS = 1, Active Low Frame Signal
= 00, Right Justify Data
= 1, Internal Serial Clock
= RFSR = 1, Frame Every Word
= 0, External Framing Signal
= 1, Internal Framing Signal
= 1001, 10-Bit Data-Words (ISHA Mode Write)
= 0111, 3 ⫻ 8-Bit Data-Words (DAC Mode Write)
= 1111, 16-Bit Data-Words (Read-Back Mode)
D OUT
MISO
SYNC
PC7
SCLK
SCK
D IN
*ADDITIONAL PINS OMITTED FOR CLARITY
Figure 12. AD5532 to MC68HC11 Interface
AD5532 to PIC16C6x/7x
The PIC16C6x/7x synchronous serial port (SSP) is configured as
an SPI master with the Clock Polarity Bit = 0. This is done by writing to the Synchronous Serial Port Control Register (SSPCON).
See the PIC16/17 Microcontroller User Manual. In this example,
the I/O port RA1 is being used to pulse SYNC and enable the
serial port of the AD5532. This microcontroller transfers only eight
bits of data during each serial transfer operation; therefore, two
or three consecutive read/write operations are needed depending
on the mode. Figure 13 shows the connection diagram.
PIC16C6x/7x*
AD5532*
SCLK
SCK/RC3
D OUT
SDO/RC5
D IN
Figure 11 shows the connection diagram.
SYNC
AD5532*
D OUT
DR
SYNC
TFS
D IN
SCLK
MOSI
ADSP-2101/
ADSP-2103*
SDI/RC4
RA1
*ADDITIONAL PINS OMITTED FOR CLARITY
Figure 13. AD5532 to PIC16C6x/7x Interface
RFS
AD5532 to 8051
DT
The AD5532 requires a clock synchronized to the serial data.
The 8051 serial interface must therefore be operated in Mode
0. In this mode, serial data enters and exits through RxD and
a shift clock is output on TxD. Figure 14 shows how the 8051 is
connected to the AD5532. Because the AD5532 shifts data out
on the rising edge of the shift clock and latches data in on the
falling edge, the shift clock must be inverted. The AD5532
requires its data with the MSB first. Since the 8051 outputs the
LSB first, the transmit routine must take this into account.
SCLK
*ADDITIONAL PINS OMITTED FOR CLARITY
Figure 11. AD5532 to ADSP-2101/ADSP-2103 Interface
AD5532 to MC68HC11
The serial peripheral interface (SPI) on the MC68HC11 is
configured for Master Mode (MSTR) = 1, Clock Polarity Bit
(CPOL) = 0, and the Clock Phase Bit (CPHA) = 1. The SPI is
configured by writing to the SPI Control Register (SPCR)—see
68HC11 User Manual. SCK of the 68HC11 drives the SCLK of
the AD5532, the MOSI output drives the serial data line (DIN)
of the AD5532, and the MISO input is driven from DOUT. The
SYNC signal is derived from a port line (PC7). When data is
being transmitted to the AD5532, the SYNC line is taken low
(PC7). Data appearing on the MOSI output is valid on the falling edge of SCK. Serial data from the 68HC11 is transmitted in
8-bit bytes with only eight falling clock edges occurring in the
transmit cycle. Data is transmitted MSB first. To transmit 10 data
bits in ISHA Mode, it is important to left-justify the data in the
SPDR Register. PC7 must be pulled low to start a transfer. It is
taken high and pulled low again before any further read/write cycles
can take place. A connection diagram is shown in Figure 12.
8051*
AD5532*
SCLK
TxD
D OUT
RxD
D IN
SYNC
P1.1
*ADDITIONAL PINS OMITTED FOR CLARITY
Figure 14. AD5532 to 8051 Interface
APPLICATION CIRCUITS
AD5532 in a Typical ATE System
The AD5532 is ideally suited for use in automatic test equipment.
Several DACs are required to control pin drivers, comparators,
active loads, and signal timing. Traditionally, sample-and-hold
devices were used in this application.
The AD5532 has several advantages: no refreshing is required,
there is no droop, pedestal error is eliminated, and there is no
need for extra filtering to remove glitches. Overall a higher level
of integration is achieved in a smaller area (see Figure 15).
–14–
REV. B
AD5532
AVCC
PARAMETRIC
MEASUREMENT SYSTEM BUS
UNIT
AVCC DVCC VSS
DAC
VDD
ACTIVE
LOAD
DAC
DAC
CS
DIN
SCLK
STORED
DATA
AND INHIBIT
PATTERN
AD5541*
AD820
AD5532*
REF
DRIVER
VIN
VOUT 0–31
OFFS_IN
OFFS_OUT
DAC
REFIN
FORMATTER
DUT
DAC
AD780*
PERIOD
GENERATION
AND
DELAY
TIMING
VOUT
DAC
SCLK DIN
COMPARE
REGISTER
SYNC
*ADDITIONAL PINS OMITTED FOR CLARITY
DAC
Figure 17. Typical Application Circuit (ISHA Mode)
COMPARATOR
DACs
SYSTEM BUS
POWER SUPPLY DECOUPLING
Figure 15. AD5532 in an ATE System
Typical Application Circuit (DAC Mode)
The AD5532 can be used in many optical networking applications
that require a large number of DACs to perform control and
measurement functions. In the example shown in Figure 16,
the outputs of the AD5532 are amplified and used to control
actuators that determine the position of MEMS mirrors in an
optical switch. The exact position of each mirror is measured
using sensors. The sensor readings are muxed using four dual
4-channel matrix switches (ADG739) and fed back to an
8-channel 14-bit ADC (AD7856).
The control loop is driven by an ADSP-2191M, a 16-bit fixedpoint DSP with 3 SPORT interfaces and 2 SPI ports. The DSP
uses some of these serial ports to write data to the DAC, control
the multiplexer, and read back data from the ADC.
1
AD5532
32
MEMS
MIRROR
ARRAY
1
32
S
E
N
S
O
R
1
ADG739
AD7856
ⴛ4
8
AD8544
ⴛ2
ADSP-2191M
Figure 16. Typical Optical Control and
Measurement Application Circuit
Typical Application Circuit (ISHA Mode)
The AD5532 can be used to set up voltage levels on 32 channels
as shown in the circuit that follows. An AD780 provides the
3 V reference for the AD5532 and for the AD5541 16-bit DAC.
A simple 3-wire interface is used to write to the AD5541. Because
the AD5541 has an output resistance of 6.25 kΩ (typ), the time
taken to charge/discharge the capacitance at the VIN pin is significant. Hence an AD820 is used to buffer the DAC output. Note
that it is important to minimize noise on VIN and REFIN when
laying out the circuit.
REV. B
In any circuit where accuracy is important, careful consideration
of the power supply and ground return layout helps to ensure
the rated performance. The printed circuit board on which the
AD5532 is mounted should be designed so that the analog and
digital sections are separated and confined to certain areas of
the board. If the AD5532 is in a system where multiple devices
require an AGND-to-DGND connection, the connection should
be made at one point only. The star ground point should be
established as close as possible to the device. For supplies with
multiple pins (VSS, VDD, AVCC) it is recommended to tie those pins
together. The AD5532 should have ample supply bypassing of
10 µF in parallel with 0.1 µF on each supply located as close to
the package as possible, ideally right up against the device. The
10 µF capacitors are the tantalum bead type. The 0.1 µF capacitor
should have low effective series resistance (ESR) and effective
series inductance (ESI), such as the common ceramic types
that provide a low impedance path to ground at high frequencies,
to handle transient currents due to internal logic switching.
The power supply lines of the AD5532 should use as large a trace as
possible to provide low impedance paths and reduce the effects
of glitches on the power supply line. Fast switching signals, such as
clocks, should be shielded with digital ground to avoid radiating
noise to other parts of the board and should never be run near the
reference inputs. A ground line routed between the DIN and SCLK
lines will help reduce crosstalk between them (not required on a
multilayer board as there will be a separate ground plane, but
separating the lines will help).
Note it is essential to minimize noise on VIN and REFIN lines.
Particularly for optimum ISHA performance, the VIN line must be
kept noise-free. Depending on the noise performance of the board,
a noise filtering capacitor may be required on the VIN line. If this
capacitor is necessary, then for optimum throughput it may be
necessary to buffer the source which is driving VIN. Avoid crossover of digital and analog signals. Traces on opposite sides of the
board should run at right angles to each other. This reduces the
effects of feedthrough through the board. A microstrip technique is
by far the best, but not always possible with a double-sided board.
In this technique, the component side of the board is dedicated to
ground plane while signal traces are placed on the solder side.
As is the case for all thin packages, care must be taken to avoid
flexing the package and to avoid a point load on the surface of
the package during the assembly process.
–15–
AD5532
OUTLINE DIMENSIONS
74-Ball Low-Profile Square Ball Grid Array [LFBGA]
(BC-74)
A1 CORNER
INDEX CORNER
C00939–0–6/02(B)
Dimensions shown in millimeters
A1 CORNER
INDEX CORNER
10.00 BSC
12.00 BSC
11 10 9 8 7 6 5 4 3 2 1
TOP VIEW
1.70
MAX
12.00
BSC
1.00
BSC
DETAIL A
COPLANARITY
0.50 MIN
BOT TOM
VIEW
A
B
C
D
E
F
G
H
J
K
L
10.00
BSC
1.00 BSC
DETAIL A
0.60 BSC
BALL DIAMETER
SEATING
PLANE
COMPLIANT TO JEDEC STANDARDS MO-192
Revision History
Location
Page
6/02—Data Sheet changed from REV. A to REV. B.
Term SHA changed to ISHA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Global
Edits to ABSOLUTE MAXIMUM RATINGS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Edits to ORDERING GUIDE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Edits to FUNCTIONAL DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Edits to Table I . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Edits to ISHA Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Figure 16 and accompanying text added . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
PRINTED IN U.S.A.
Edits to POWER SUPPLY DECOUPLING section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
–16–
REV. B