4
LTC1821
Note 8: To 0.0015% for a full-scale change, measured from the rising
edge of LD.
Note 9: REF
= 0V. DAC register contents changed from all 0s to all 1s or all
1s to all 0s. LD low and WR high.
Note 10: Midscale transition code: 0111 1111 1111 1111 to
1000 0000 0000 0000. Unipolar mode, C
FEEDBACK
= 33pF.
Note 11: R1 and R2 are measured between R1 and R
COM
, REF and R
COM
.
Note 1: Absolute Maximum Ratings are those values beyond which the life
of a device may be impaired.
Note 2: ±1LSB = ±0.0015% of full scale = ±15.3ppm of full scale.
Note 3: Using internal feedback resistor.
Note 4: Guaranteed by design, not subject to test.
Note 5: I
OUT
with DAC register loaded to all 0s.
Note 6: Typical temperature coefficient is 100ppm/°C.
Note 7: Measured in unipolar mode.
ELECTRICAL CHARACTERISTICS
TYPICAL PERFOR A CE CHARACTERISTICS
UW
TIME (µs)
0
OUTPUT VOLTAGE (mV)
–10
0
10
0.6
1.0
1821 G01
–20
–30
–40
0.2 0.4 0.8
20
30
40
C
FEEDBACK
= 30pF
V
REF
= 10V
1nV-s TYPICAL
FREQUENCY (Hz)
–90
SIGNAL/(NOISE + DISTORTION) (dB)
–70
–50
–40
10 1k 10k 100k
1821 G03
–110
100
–60
–80
–100
V
CC
= 5V
C
FEEDBACK
= 30pF
REFERENCE = 6V
RMS
500kHz FILTER
80kHz FILTER
30kHz FILTER
LD PULSE
5V/DIV
GATED
SETTLING
WAVEFORM
500µV/DIV
500ns/DIV
1821 G02
V
REF
= –10V
C
FEEDBACK
= 20pF
0V TO 10V STEP
FREQUENCY (Hz)
–90
SIGNAL/(NOISE + DISTORTION) (dB)
–70
–50
–40
10 1k 10k 100k
1821 G04
–110
100
–60
–80
–100
V
CC
= 5V USING AN LT1468
C
FEEDBACK
= 15pF
REFERENCE = 6V
RMS
500kHz FILTER
80kHz FILTER
30kHz
FILTER
FREQUENCY (Hz)
–90
SIGNAL/(NOISE + DISTORTION) (dB)
–70
–50
–40
10 1k 10k 100k
1821 G05
–110
100
–60
–80
–100
V
CC
= 5V USING AN LT1468
C
FEEDBACK
= 15pF
REFERENCE = 6V
RMS
500kHz FILTER
80kHz FILTER
30kHz FILTER
INTPUT VOLTAGE (V)
0
SUPPLY CURRENT (mA)
3
4
5
4
1821 G06
2
1
0
1
2
3
5
V
CC
= 5V
ALL DIGITAL INPUTS
TIED TOGETHER
Midscale Glitch Impulse
Unipolar Multiplying Mode
Signal-to-(Noise + Distortion)
vs Frequency
Full-Scale Setting Waveform
Bipolar Multiplying Mode
Signal-to-(Noise + Distortion)
vs Frequency, Code = All Zeros
Bipolar Multiplying Mode
Signal-to-(Noise + Distortion)
vs Frequency, Code = All Ones
V
CC
Supply Current vs Digital
Input Voltage
