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AD7945BR

P1-P3P4-P6P7-P9P10-P12P13-P15P16-P16
FUNCTIONAL BLOCK DIAGRAMS
V
DD
R
FB
DGND
AD7948
DB7–DB0
DF/DOR
CTRL
LDAC
WR
CSLSB
CSMSB
I
OUT1
AGND
V
REF
12-BIT DAC
12
12
DATA OVERRIDE LOGIC
12
DAC REGISTER
12
INPUT REGISTERS
CONTROL
LOGIC
DATA STEERING LOGIC
8
CS
WR
V
DD
R
FB
I
OUT1
AGND
V
REF
DGNDDB11–DB0
AD7945
12-BIT DAC
12
INPUT LATCH
12
AD7943
V
DD
R
FB
I
OUT1
AGND
I
OUT2
SRO
STB1 DGNDSTB2
STB3
STB4
CLR
LD1
LD2
SRI
V
REF
12-BIT DAC
DAC REGISTER
INPUT SHIFT REGISTER
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
which may result from its use. No license is granted by implication or
otherwise under any patent or patent rights of Analog Devices.
a
+3.3 V/+5 V Multiplying
12-Bit DACs
AD7943/AD7945/AD7948
FEATURES
12-Bit Multiplying DACs
Guaranteed Specifications with +3.3 V/+5 V Supply
0.5 LSBs INL and DNL
Low Power: 5 mW typ
Fast Interface
40 ns Strobe Pulsewidth (AD7943)
40 ns Write Pulsewidth (AD7945, AD7948)
Low Glitch: 60 nV-s with Amplifier Connected
Fast Settling: 600 ns to 0.01% with AD843
APPLICATIONS
Battery-Powered Instrumentation
Laptop Computers
Upgrades for All 754x Series DACs (5 V Designs)
GENERAL DESCRIPTION
The AD7943, AD7945 and AD7948 are fast 12-bit multiplying
DACs that operate from a single +5 V supply (Normal Mode)
and a single +3.3 V to +5 V supply (Biased Mode). The
AD7943 has a serial interface, the AD7945 has a 12-bit parallel
interface, and the AD7948 has an 8-bit byte interface. They will
replace the industry-standard AD7543, AD7545 and AD7548
in many applications, and they offer superior speed and power
consumption performance.
The AD7943 is available in 16-lead DIP, 16-lead SOP (Small
Outline Package) and 20-lead SSOP (Shrink Small Outline
Package).
The AD7945 is available in 20-lead DIP, 20-lead SOP and 20-
lead SSOP.
The AD7948 is available in 20-lead DIP, 20-lead SOP and 20-
lead SSOP.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781/329-4700 World Wide Web Site: http://www.analog.com
Fax: 781/326-8703 © Analog Devices, Inc., 1998
REV. B
–2–
AD7943/AD7945/AD7948–SPECIFICATIONS
1
Parameter B Grades
2
T Grade
2, 3
Units Test Conditions/Comments
ACCURACY
Resolution 12 12 Bits 1 LSB = V
REF
/2
12
= 2.44 mV when V
REF
=10V
Relative Accuracy ±0.5 ±0.5 LSB max
Differential Nonlinearity ±0.5 ±0.5 LSB max All Grades Guaranteed Monotonic over
Temperature
Gain Error
T
MIN
to T
MAX
±2 ±2 LSB max
Gain Temperature Coefficient
4
2 2 ppm FSR/°C typ
5 5 ppm FSR/°C max
Output Leakage Current
I
OUT1
@ +25°C 10 10 nA max See Terminology Section
T
MIN
to T
MAX
100 100 nA max Typically 20 nA over Temperature
REFERENCE INPUT
Input Resistance 6 6 kΩ min Typical Input Resistance = 9 kΩ
12 12 kΩ max
DIGITAL INPUTS
V
INH
, Input High Voltage 2.4 2.4 V min
V
INL
, Input Low Voltage 0.8 0.8 V max
I
INH
, Input Current ±1 ±1 µA max
C
IN
, Input Capacitance
4
10 10 pF max
DIGITAL OUTPUT (AD7943 SRO) For 1 CMOS Load
Output Low Voltage (V
OL
) 0.2 0.2 V max
Output High Voltage (V
OH
)V
DD
– 0.2 V
DD
– 0.2 V min
POWER REQUIREMENTS
V
DD
Range 4.5/5.5 4.5/5.5 V min/V max
Power Supply Sensitivity
4
∆Gain/∆V
DD
–75 –75 dB typ
I
DD
(AD7943) 5 5 µA max V
INH
= V
DD
– 0.1 V min, V
INL
= 0.1 V max.
SRO Open Circuit. No STB Signal. Typically
1 µA. Typically 100 µA with a 1 MHz STB
Frequency. At Input Levels of 0.8 V and 2.4 V,
I
DD
Is Typically 2.5 mA.
I
DD
(AD7945, AD7948) 5 5 µA max V
INH
= V
DD
– 0.1 V min, V
INL
= 0.1 V max.
Typically 1 µA. At Input Levels of 0.8 V and
2.4 V, I
DD
Is Typically 2.5 mA.
NOTES
1
The AD7943, AD7945 and AD7948 are specified in the normal current mode configuration and in the biased current mode for single-supply applications.
Figures 14 and 15 are examples of normal mode operation.
2
Temperature ranges as follows: B Grades: –40°C to +85°C; T Grade: –55°C to +125°C.
3
The T Grade applies to the AD7945 only.
4
Guaranteed by design.
Specifications subject to change without notice.
NORMAL MODE
(AD7943: V
DD
= +4.5 V to +5.5 V; V
IOUT1
= V
IOUT2
= AGND = 0 V; V
REF
= +10 V; T
A
= T
MIN
to T
MAX
, unless otherwise noted.
AD7945, AD7948: V
DD
= +4.5 V to +5.5 V; V
IOUT1
= AGND = 0 V; V
REF
= +10 V; T
A
= T
MIN
to T
MAX
, unless otherwise noted.)
AD7943/AD7945/AD7948
REV. B
–3–
Parameter A Grades
2
Units Test Conditions/Comments
ACCURACY
Resolution 12 Bits 1 LSB = (V
IOUT1
– V
REF)
/2
12
= 300 µV When
V
IOUT1
= 1.23 V and V
REF
= 0 V
Relative Accuracy ±1 LSB max
Differential Nonlinearity ±0.9 LSB max All Grades Guaranteed Monotonic
over Temperature
Gain Error @ +25°C ±3 LSB max
T
MIN
to T
MAX
±4 LSB max
Gain Temperature Coefficient
3
2 ppm FSR/°C typ
5 ppm FSR/°C max
Output Leakage Current See Terminology Section
I
OUT1
@ +25°C 10 nA max
T
MIN
to T
MAX
100 nA max Typically 20 nA over Temperature
Input Resistance This Varies with DAC Input Code
@ I
OUT2
Pin (AD7943) 6 kΩ min
@ AGND Pin (AD7945, AD7948) 6 kΩ min
DIGITAL INPUTS
V
INH
, Input High Voltage @ V
DD
= +5 V 2.4 V min
V
INH
, Input High Voltage @ V
DD
= +3.3 V 2.1 V min
V
INL
, Input Low Voltage @ V
DD
= +5 V 0.8 V max
V
INL
, Input Low Voltage @ V
DD
= +3.3 V 0.6 V max
I
INH
, Input Current ±1 µA max
C
IN
, Input Capacitance
3
10 pF max
DIGITAL OUTPUT (SRO) For 1 CMOS Load
Output Low Voltage (V
OL
) 0.2 V max
Output High Voltage (V
OH
)V
DD
– 0.2 V min
POWER REQUIREMENTS
V
DD
Range 3.0/5.5 V min/V max
Power Supply Sensitivity
3
∆Gain/∆V
DD
–75 dB typ
I
DD
(AD7943) 5 µA max V
INH
= V
DD
– 0.1 V min, V
INL
= 0.1 V max.
SRO Open Circuit; No STB Signal; Typically
1 µA. Typically 100 µA with 1 MHz STB
Frequency.
I
DD
(AD7945, AD7948) 5 µA max V
INH
= V
DD
– 0.1 V min, V
INL
= 0.1 V max.
Typically 1 µA.
NOTES
1
These specifications apply with the devices biased up at 1.23 V for single supply applications. The model numbering reflects this by means of a “–B” suffix
(for example: AD7943AN-B). Figure 16 is an example of Biased Mode Operation.
2
Temperature ranges as follows: A Versions: –40°C to +85°C.
3
Guaranteed by design.
Specifications subject to change without notice.
BIASED MODE
SPECIFICATIONS
1
(AD7943: V
DD
= +3 V to +5.5 V; V
IOUT1
=V
IOUT2
= AGND = 1.23 V; V
REF
= +0 V to 2.45 V; T
A
= T
MIN
to T
MAX
, unless other-
wise noted. AD7945, AD7948: V
DD
= +3 V to +5.5 V; V
IOUT1
= AGND = 1.23 V; V
REF
= +0 V to 2.45 V; T
A
= T
MIN
to T
MAX
, unless otherwise noted.)
P1-P3P4-P6P7-P9P10-P12P13-P15P16-P16

AD7945BR

Mfr. #:
Buy AD7945BR
Manufacturer:
Analog Devices Inc.
Description:
Digital to Analog Converters - DAC 3.3V/5V Multiplying 12-Bit Parallel IF
Lifecycle:
New from this manufacturer.
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