T
A
= –408CT
A
= –558C
Parameter T
A
= +258C
1
to +858C to +1258C
1
Units Test Conditions/Comments
STATIC PERFORMANCE
2
Resolution 8 8 8 Bits
Relative Accuracy ±1/2 ±1/2 ±1/2 LSB max This is an Endpoint Linearity Specification
Differential Nonlinearity ±1 ±1 ±l LSB max All Grades Guaranteed Monotonic Over
Full Operating Temperature Range
Gain Error ±2 ±3 ±3 LSB max Measured Using Internal RFB A and RFB B.
Both DAC Latches Loaded with 11111111.
Gain Error is Adjustable Using Circuits
of Figures 4 and 5.
Gain Temperature Coefficient
3
∆Gain/∆Temperature ±0.0035 ±0.0035 %/°C max
Output Leakage Current
OUT A (Pin 2) ±50 ±200 ±200 nA max DAC Latches Loaded with 00000000
OUT B (Pin 20) ±50 ±200 ±200 nA max
Input Resistance (V
REF
A, V
REF
B)88 8kΩ min Input Resistance TC = –300 ppm/°C, Typical
15 15 15 kΩ max Input Resistance is 11 kΩ
V
REF
A/V
REF
B Input Resistance
Match ±1 ±1 ±1 % max
DIGITAL INPUTS
4
Input High Voltage (V
IH
) 2.4 2.4 2.4 V min
Input Low Voltage (V
IL
) 0.8 0.8 0.8 V max
Input Current (I
IN
) ±1 ±10 ±10 µA max V
IN
= 0 or V
DD
Input Capacitance
DB0–DB7 10 10 10 pF max
WR, CS, DACA/DACB 15 15 15 pF max
SWITCHING CHARACTERISTICS
3
See Timing Diagram
Chip Select to Write Set Up Time (t
CS
) 160 160 210 ns min
Chip Select to Write Hold Time (t
CH
) 10 10 10 ns min
DAC Select to Write Set Up Time (t
AS
) 160 160 210 ns min
DAC Select to Write Hold Time (t
AH
) 10 10 10 ns min
Data Valid to Write Set Up Time (t
DS
) 160 160 210 ns min
Data Valid to Write Hold Time (t
DH
) 10 10 10 ns min
Write Pulse Width (t
WR
) 150 170 210 ns min
POWER SUPPLY See Figure 3
I
DD
, K Grade 2 2 mA All Digital Inputs V
IL
or V
IH
B, T Grades 2 2.5 2.5 mA All Digital Inputs V
IL
or V
IH
All Grades 100 500 500 µA All Digital Inputs 0 V or V
DD
Specifications subject to change without notice.
AC PERFORMANCE CHARACTERISTICS
T
A
= –408CT
A
= –558C
Parameter T
A
= +258C
1
to +858C
1
to +1258πC
1
Units Test Conditions/Comments
DC SUPPLY REJECTION
(∆GAIN/∆V
DD
) 0.01 0.02 0.02 % per % max ∆V
DD
= ±5%
CURRENT SETTLING TIME 350 400 400 ns max To 1/2 LSB OutA/OutB Load = 100 Ω.
WR = CS = 0 V.
DB0–DB7 = 0 V to V
DD
or V
DD
to 0 V
DIGITAL-TO-ANALOG GLITCH
IMPULSE 330 nV sec typ For Code Transition 00000000 to 11111111
OUTPUT CAPACITANCE
C
OUT
A 25 25 25 pF max DAC Latches Loaded with 00000000
C
OUT
B 25 25 25 pF max
C
OUT
A 60 60 60 pF max DAC Latches Loaded with 11111111
C
OUT
B 60 60 60 pF max
AC FEEDTHROUGH
V
REF
A to OUT A –70 –65 –65 dB max V
REF
A, V
REF
B = 20 V p-p Sine Wave
V
REF
B to OUT B –70 –65 –65 dB max @ 10 kHz
CHANNEL-TO-CHANNEL ISOLATION Both DAC Latches Loaded with 11111111.
V
REF
A to OUT B –80 dB typ V
REF
A = 20 V p-p Sine Wave @ 10 kHz
V
REF
B = 0 V See Figure 6.
V
REF
B to OUTA –80 dB typ V
REF
B = 20 V p-p Sine Wave @ 10 kHz
V
REF
A = 0 V See Figure 6.
DIGITAL CROSSTALK 60 nV sec typ Measured for Code Transition 00000000
to 11111111
HARMONIC DISTORTION –85 dB typ V
IN
= 6 V rms @ 1 kHz
NOTES
1
Temperature Ranges are K Version; –40°C to +85°C; B Version; –40°C to +85°C; T Version; –55°C to +125°C.
2
Specification applies to both DACs in AD7628.
3
Guaranteed by design but not production tested.
4
Logic inputs are MOS Gates. Typical input current (+25°C) is less than 1 nA.
Specifications subject to change without notice.
REV. A
–2–
AD7628–SPECIFICATIONS
(V
DD
= +10.8 V to +15.75 V, V
REF
A = V
REF
B = +10 V; OUT A = OUT B = 0 V unless
otherwise noted)
These characteristics are included for Design Guidance only and are not
subject to test. V
DD
= +10.8 V to +15.75 V. (Measured Using Recommended PC Board Layout (Figure 7) and AD644 as Output Amplifiers)
