廬
IVC102
PRECISION SWITCHED INTEGRATOR
TRANSIMPEDANCE AMPLIFIER
APPLICATIONS
q
PRECISION LOW CURRENT MEASUREMENT
q
PHOTODIODE MEASUREMENTS
q
IONIZATION CHAMBER MEASUREMENTS
q
CURRENT/CHARGE-OUTPUT SENSORS
q
LEAKAGE CURRENT MEASUREMENT
DESCRIPTION
The IVC102 is a precision integrating amplifier with
FET op amp, integrating capacitors, and low leakage
FET switches. It integrates low-level input current for
a user-determined period, storing the resulting voltage
on the integrating capacitor. The output voltage can be
held for accurate measurement. The IVC102 provides
a precision, lower noise alternative to conventional
transimpedance op amp circuits that require a very
high value feedback resistor.
The IVC102 is ideal for amplifying low-level sensor
currents from photodiodes and ionization chambers.
The input signal current can be positive or negative.
TTL/CMOS-compatible timing inputs control the inte-
gration period, hold and reset functions to set the
effective transimpedance gain and to reset (discharge)
the integrator capacitor.
Package options include 14-Pin plastic DIP and SO-14
surface-mount packages. Both are specified for the
鈥?0擄C to 85擄C industrial temperature range.
V+
FEATURES
q
ON-CHIP INTEGRATING CAPACITORS
q
GAIN PROGRAMMED BY TIMING
q
LOW INPUT BIAS CURRENT: 750fA max
q
LOW NOISE
q
LOW SWITCH CHARGE INJECTION
q
FAST PULSE INTEGRATION
q
LOW NONLINEARITY: 0.005% typ
q
14-PIN DIP, SO-14 SURFACE MOUNT
6
V
B
5
Ionization
Chamber
I
IN
4
3
2
S
1
1
C
1
C
2
C
3
30pF
60pF
14
V
O
=
鈥?
I (t) dt
C
INT IN
鈭?/div>
10pF
S
2
10
V
O
0V
Positive or Negative
Signal Integration
Hold
Integrate
Hold
Reset
9
Photodiode
Analog
Ground
11
S
1
12
S
2
13
V鈥?/div>
S
1
S
2
Logic Low closes switches
Digital
Ground
InternationalAirportIndustrialPark 鈥?MailingAddress:POBox11400 鈥?Tucson,AZ85734 鈥?StreetAddress:6730S.TucsonBlvd. 鈥?Tucson,AZ 85706
Tel:(520)746-1111 鈥?Twx:910-952-1111 鈥?Cable:BBRCORP 鈥?Telex:066-6491 鈥?FAX:(520)889-1510 鈥?ImmediateProductInfo:(800)548-6132
廬
漏 1996 Burr-Brown Corporation
1
PDS-1329A
IVC102
June, 1996
Printed in U.S.A.
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