AD7835—Parallel 8-/14-Bit Loading
Voltage Outputs
Power-On Reset Function
Max/Min Output Voltage Range of +/–8.192 V
Maximum Output Voltage Span of 14 V
Common Voltage Reference Inputs
User Assigned Device Addressing
Clear Function to User-Defined Voltage
Surface Mount Packages
AD7834—28-Pin SO, DIP and Cerdip
AD7835—44-Pin PQFP and PLCC
APPLICATIONS
Process Control
Automatic Test Equipment
General Purpose Instrumentation
Quad 14-Bit DAC
AD7834/AD7835
GENERAL DESCRIPTION
The AD7834 and AD7835 contain four 14-bit DACs on one
monolithic chip. The AD7834 and AD7835 have output voltages in the range of ±8.192 V with a maximum span of 14 V.
The AD7834 is a serial input device. Data is loaded in 16-bit
format from the external serial bus, MSB first after two leading
0s, into one of the input latches via DIN, SCLK and
The AD7834 has five dedicated package address pins, PA0–
PA4, that can be wired to AGND or V
to permit up to 32
CC
AD7834s to be individually addressed in a multipackage
application.
The AD7835 can accept either 14-bit parallel loading or
double-byte loading, where right-justified data is loaded in one
8-bit and one 6-bit byte. Data is loaded from the external bus
into one of the input latches under the control of the
BYSHF and DAC channel address pins, A0–A2.
With either device, the
LDAC signal can be used to update
either all four DAC outputs simultaneously or individually,
on reception of new data. In addition, for either device, the
asynchronous
V
1–V
OUT
CLR input can be used to set all signal outputs,
4, to the user-defined voltage level on the Device
OUT
Sense Ground pin, DSG. On power-on, before the power supplies have stabilized, internal circuitry holds the DAC output
voltage levels to within ±2 V of the DSG potential. As the supplies stabilize, the DAC output levels move to the exact DSG
potential (assuming
CLR is exercised).
The AD7834 is available in 28-pin 0.3" SO and 0.6" DIP packages, and the AD7835 is available in a 44-pin PQFP package
and a 44-pin PLCC package.
FSYNC.
WR, CS,
AD7834 FUNCTIONAL BLOCK DIAGRAM
V
VDDV
CC
PA0
PA1
PA2
PA3
PA4
DIN
SCLK
AD7834
CONTROL
ADDRESS
DECODE
SERIAL-TOPARALLEL
CONVERTER
LOGIC
&
AGND
PAEN
FSYNC
REV. A
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
which may result from its use. No license is granted by implication or
otherwise under any patent or patent rights of Analog Devices.
REGISTER
REGISTER
REGISTER
REGISTER
INPUT
1
INPUT
2
INPUT
3
INPUT
4
DGND
SS
DAC 1
LATCH
DAC 2
LATCH
DAC 3
LATCH
DAC 4
LATCH
LDAC
V
(–)
(+)
V
REF
REF
DAC 1
DAC 2
DAC 3
DAC 4
DSG
X1
X1
X1
X1
V
V
V
V
CLR
OUT
OUT
OUT
OUT
1
2
3
4
One Technology Way, P.O. Box 9106, Norwood. MA 02062-9106, U.S.A.
Tel: 617/329-4700Fax: 617/326-8703
(VCC = +5 V ± 5%; VDD = +15 V ± 5%; VSS = –15 V ± 5%; AGND =
AD7834/AD7835–SPECIFICATIONS
P
arameterABSUnitsTest Conditions/Comments
DGND = 0 V; T
ACCURACY
Resolution141414Bits
Relative Accuracy±2±1±2LSB max
Differential Nonlinearity±0.9±0.9±0.9LSB maxGuaranteed Monotonic Over Temperature
Full-Scale ErrorV
to T
T
MIN
MAX
±5±5±8mV max
Zero-Scale Error±4±4±5mV maxV
Gain Error±0.5±0.5±0.5mV typV
Gain Temperature Coefficient
DC Crosstalk
2
2
444ppm FSR/°C typ
202020ppm FSR/°C max
505050µV maxSee Terminology. RL = 10 kΩ
REFERENCE INPUTS
DC Input Resistance303030MΩ typ
Input Current±1±1±1µA maxPer Input
(+) Range0/+8.192+7/+8.192 0/+8.192 V min/max
V
REF
(–) Range–8.192/0–8.192/0–8.192/0 V min/max
V
REF
[V
REF
(+)–V
(–)]5/147/145/14V min/maxFor Specified Performance. Can Go as Low as
REF
DEVICE SENSE GROUND INPUTS
Input Current±2±2±2µA maxPer Input. V
DIGITAL INPUTS
, Input High Voltage2.42.42.4V min
V
INH
, Input Low Voltage0.80.80.8V max
V
INL
, Input Current±10± 10±10µA max
I
INH
CIN, Input Capacitance101010pF max
POWER REQUIREMENTS
V
CC
V
DD
V
SS
5.05.05.0V nom±5% for Specified Performance
15.015.015.0V nom±5% for Specified Performance
–15.0–15.0–15.0V nom± 5% for Specified Performance
Power Supply Sensitivity
∆Full Scale/∆V
∆Full Scale/∆V
I
CC
DD
SS
110110110dB typ
100100100dB typ
0.20.20.5mA maxV
333mA maxAD7834. V
666mA maxAD7835. V
I
DD
101015mA maxAD7834. Outputs Unloaded
151515mA maxAD7835. Outputs Unloaded
I
SS
101015mA maxOutputs Unloaded
1
= T
to T
A
MIN
, unless otherwise noted)
MAX
(+) = +7 V, V
REF
(+) = +7 V, V
REF
(+) = +7 V, V
REF
(–) = –7 V
REF
(–) = –7 V
REF
(–) = –7 V
REF
0 V, but Performance Not Guaranteed
= –2 V to +2 V
DSG
= VCC, V
INH
= DGND
INL
= 2.4 V min, V
INH
= 2.4 V min, V
INH
= 0.8 V max
INL
= 0.8 V max
INL
(These characteristics are included for Design Guidance and are not
AC PERFORMANCE CHARACTERISTICS
P
arameterABSUnitsTest Conditions/Comments
DYNAMIC PERFORMANCE
Output Voltage Settling Time101010µs typFull-Scale Change to ±1/2 LSB. DAC Latch Contents
Digital-to-Analog Glitch Impulse120120120nV-s typMeasured with V
DC Output Impedance0.50.50.5Ω typSee Terminology
Channel-to-Channel Isolation100100100dB typSee Terminology; Applies to the AD7835 Only
DAC to DAC Crosstalk252525nV-s typSee Terminology
Digital Crosstalk333nV-s typFeedthrough to DAC Output Under Test Due to
Digital Feedthrough – AD78340.20.20.2nV-s typEffect of Input Bus Activity on DAC Output Under Test
Digital Feedthrough – AD78340.10.10.1nV-s typ
Output Noise Spectral Density
@ 1 kHz404040nV/√Hz typAll 1s Loaded to DAC. V
NOTES
1
Temperature range is as follows: A Version: –40°C to +85°C; B Version: –40°C to +85°C; S Version: –55°C to +125°C.
2
Guaranteed by design.
Specifications subject to change without notice
subject to production testing. )
Alternately Loaded with All 0s and All 1s
Alternately Loaded with All 0s and All 1s
Change in Digital Input Code to Another Converter
–2–
REF
(+) = V
REF
(–) = 0 V. DAC Latch
REF
(+) = V
(–) = 0 V
REF
REV. A
TIMING SPECIFICATIONS
t
12
t
14
t
17
t
16
t
15
t
10
t
18
t
19
t
11
t
13
A0. A1 A2
BYSHF
CS
WR
DATA
LDAC
(SIMULTANEOUS
UPDATE)
LDAC
(PRE-CHANNEL
UPDATE)
AD7834/AD7835
1
(VCC = +5 V ± 5%; VDD = +15 V ± 5%; VSS = –15 V ± 5%; AGND = DGND = 0 V)
ParameterLimit at T
AD7834 Specific
2
t
1
2
t
2
100ns minSCLK Cycle Time
50ns minSCLK Low Time @ +25°C
MIN, TMAX
UnitsDescription
60ns minSCLK Low Time –40°C to +85°C
2
t
3
t
4
t
5
t
6
t
7
t
8
t
9
t
21
66ns minSCLK Low Time –55°C to +125°C
30ns minSCLK High Time
30ns minFSYNC, PAEN Setup Time
40ns minFSYNC, PAEN Hold Time
30ns minData Setup Time
10ns minData Hold Time
0ns minLDAC to FSYNC Setup Time
40ns minLDAC to FSYNC Hold Time
20ns minDelay Between Write Operations
AD7835 Specific
t
11
t
12
t
13
t
14
t
15
t
16
t
17
t
18
t
19
t
20
15ns minA0, A1, A2, BYSHF to CS Setup Time
15ns minA0, A1, A2, BYSHF to CS Hold Time
0ns minCS to WR Setup Time
0ns minCS to WR Hold Time
40ns minWR Pulse Width
40ns minData Setup Time
10ns minData Hold Time
0ns minLDAC to CS Setup Time
0ns minCS to LDAC Setup Time
0ns minLDAC to CS Hold Time
General
t
10
NOTES
1
All input signals are specified with tr = tf = 5 ns (10% to 90% of 5 V) and timed from a voltage level of 1.6 V.
2
Rise and fall times should be no longer than 50 ns.
Specifications subject to change without notice.
40ns minLDAC, CLR Pulse Width
FSYNC
(SIMULTANEOUS
LDAC
UPDATE)
LDAC
(PRE-CHANNEL
UPDATE)
REV. A
1ST
2ND
CLK
CLK
SCLK
t
4
t
6
t
7
DIN
Figure 1. AD7834 Timing Diagram
D0D1
t
8
t
1
t
t
2
24TH
CLK
D23
t
5
t
20
t
10
t
9
3
D22
Figure 2. AD7835 Timing Diagram
–3–
AD7834/AD7835
WARNING!
ESD SENSITIVE DEVICE
ABSOLUTE MAXIMUM RATINGS
(TA = +25°C unless otherwise noted)
VCC to DGND . . . . . . . . . . . . . . . –0.3 V, +7 V or V
Stresses above those listed under “Absolute Maximum 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
operational section 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.
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 AD7834/AD7835 feature 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.
ORDERING GUIDE
Linearity
TemperatureErrorDNLPackage
ModelRange(LSBs)(LSBs)Option
AD7834AR–40°C to +85°C±2±0.9R-28
AD7834BR–40°C to +85°C±1±0.9R-28
AD7834AN–40°C to +85°C±2± 0.9N-28
AD7834BN–40°C to +85°C±1±0.9N-28
AD7834SQ–55°C to +125°C±2± 0.9Q-28
AD7835AS
AD7835BS
AD7835AP
NOTES
1
R = Small Outline IC (SOIC); N = Plastic DIP; Q = Cerdip; S = Plastic Quad Flatpack (PQFP);
P = Plastic Leaded Chip Carrier (PLCC).
2
Contact Sales Office for availability.
2
2
2
–40°C to +85°C±2± 0.9S-44
–40°C to +85°C±1± 0.9S-44
–40°C to +85°C±2± 0.9P-44A
1
–4–
REV. A
Pin MnemonicDescription
AD7834/AD7835
AD7834 PIN DESCRIPTION
V
CC
V
SS
V
DD
Logic Power Supply; +5 V ± 5%.
Negative Analog Power Supply; –15 V ± 5%.
Positive Analog Power Supply; +15 V ± 5%.
DGNDDigital Ground.
AGNDAnalog Ground.
(+)Positive Reference Input. The positive reference voltage is referred to AGND.
V
REF
(–)Negative Reference Input. The negative reference voltage is referred to AGND.
V
REF
1...V
V
OUT
DSGDevice Sense Ground Input. Used in conjunction with the
4DAC Outputs.
OUT
When
CLR input for power-on protection of the DACs.
CLR is low, the DAC outputs are forced to the potential on the DSG pin.
DINSerial Data Input.
SCLKClock input for writing data to the device.
FSYNCFrame Sync Input. Active low logic input used, in conjunction with DIN and SCLK, to write data to the device
with serial data expected after the falling edge of this signal. The contents of the 24-bit serial-to-parallel input
register are transferred on the rising edge of this signal.
PA0 . . . PA4Package Address Inputs. These inputs are hardwired high (V
) or low (DGND) to assign dedicated package
CC
addresses in a multipackage environment.
PAENPackage Address Enable Input. When low, this input allows normal operation of the device. When it is high, the
device ignores the package address (but not the channel address) in the serial data stream and loads the serial
data into the input registers. This feature is useful in a multipackage application where it can be used to load the
same data into the same channel in each package.
LDACLoad DAC Input (level sensitive). This input signal in conjunction with the FSYNC input signal, determines
how the analog outputs are updated. If
device’s input registers, no change occurs on the analog outputs. Subsequently, when
LDAC is maintained high while new data is being loaded into the
LDAC is brought low, the
contents of all four input registers are transferred into their respective DAC latches, updating the analog outputs.
Alternatively, if
corresponding analog output) is updated immediately on the rising edge of
LDAC is kept low while new data is shifted into the device, then the addressed DAC latch (and
FSYNC.
CLRAsynchronous Clear Input (level sensitive, active low). When this input is brought low, all analog outputs are
switched to the externally set potential on the DSG pin. When
the DSG potential until
LDAC is brought low. When LDAC is brought low, the analog outputs are switched
back to reflect their individual DAC output levels. As long as
CLR is brought high, the signal outputs remain at
CLR remains low, the LDAC signals are ignored
and the signal outputs remain switched to the potential on the DSG pin.
REV. A
PIN CONFIGURATION
DIP AND SOIC
28
27
26
25
24
23
22
21
20
19
18
17
16
15
AGND
NC
NC
NC
NC
V
DD
V
OUT
V
OUT
CLR
LDAC
FSYNC
PAEN
PA4
PA3
1
3
V
REF
V
REF
V
V
DGND
SCLK
V
DSG
OUT
OUT
V
DIN
PA0
PA1
PA2
SS
(–)
(+)
NC
2
4
CC
1
2
3
4
5
AD7834
6
TOP VIEW
(Not to Scale)
7
8
9
10
11
12
13
14
NC = NO CONNECT
–5–
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