LT1021 Datasheet, PDF (12/16 Pages) Linear Technology – Precision Reference

LT1021
TYPICAL APPLICATIONS
Boosted Output Current
with No Current Limit
Boosted Output Current
with Current Limit
V⁺ ≥ (V_OUT + 1.8V)
R1
220Ω
IN
LT1021
OUT
GND
2N2905
10V AT
100mA
+ 2µF
SOLID
TANT
1021 TA05
V ⁺ ≥ V_OUT + 2.8V
D1* R1
LED 220Ω
8.2Ω
IN
LT1021
OUT
GND
2N2905
10V AT
100mA
+ 2µF
SOLID
TANT
1021 TA06
*GLOWS IN CURRENT LIMIT,
DO NOT OMIT
Ultraprecise Current Source
LT1021-7
15V IN
OUT
GND
17.4k
1%
TRIM
100Ω
15V
7
2
6
LT1001
3
6.98k*
0.1%
*LOW TC
4
– 15V
I_OUT = 1mA
REGULATION < 1ppm/V
COMPLIANCE = –13V TO 7V
1021 TA07
2-Pole Lowpass Filtered Reference
1µF
MYLAR
LT1021
V_IN ^IN
OUT
R1
R2
GND
36k
36k
f = 10Hz
V_IN
–
LT1001
+
0.5µF
MYLAR
V_REF
TOTAL NOISE
≤ 2µV_RMS
1Hz ≤ f ≤ 10kHz
Operating 5V Reference from 5V Supply
CMOS LOGIC GATE**
f_IN ≥ 2kHz*
1N914
1N914
LT1021-5
≈ 8.5V _IN
OUT
C1*
5µF
+
C2*
5µF
GND
5V LOGIC
SUPPLY
5V
REFERENCE
*FOR HIGHER FREQUENCIES C1 AND C2 MAY BE DECREASED
**PARALLEL GATES FOR HIGHER REFERENCE CURRENT LOADING
1021 TA16
–V_REF
1021 TA13
CMOS DAC with Low Drift Full-Scale Trimming**
OUT
LT1021-10
TRIM
GND
1.2k
–15V
12
R1
4.99k
1%
R2
40.2Ω
1%
FB
CMOS
DAC
I_OUT
7520, ETC
REF
*TC LESS THAN 200ppm/°C
**NO ZERO ADJUST REQUIRED
WITH LT1007 (V_0S ≤ 60µV)
R3
4.02K
1%
30pF
–
LT1007C
+
R4*
100Ω
FULL-SCALE
ADJUST
10V
F.S.
LT1236 TA15
Trimming 10V Units to 10.24V
LT1021-10
V_IN IN
OUT
TRIM GND
V_OUT = 10.24V
4.32k
5k
V ^– = –15V*
*MUST BE WELL REGULATED
dV_OUT
dV ^–
=
15mV
V
1021 TA12