LT1311_15 Datasheet, PDF (1/8 Pages) Linear Technology – Quad 12MHz, 145ns Settling Precision Current-to-Voltage Converter for Optical Disk Drives

LT1311
Quad 12MHz, 145ns Settling
Precision Current-to-Voltage
Converter for Optical Disk Drives
FEATURES
s _{Four Complete Current-to-Voltage Converters}
s _{14-Lead Small Outline Package}
s _{Accurate Gain: 20mV/µA, ±4%}
s _{Low Offset Error: 250nA Max}
s _{Low Offset Drift: 2.5nA/°C Max}
s _{Fast Settling: 145ns to 0.1% for a 2V Step}
s _{Wide Bandwidth: 12MHz}
s _{Low Noise: 5pA/√Hz}
s _{Low Quiescent Current: 11mA Max}
s _{Wide Supply Range: ±2V to ±18V or 4V to 36V}
U
APPLICATIONS
s _{Optical Disk Drive}
Photo Diode Amplifiers
Focus and Tracking Summing Amplifiers
s _{Color Scanners}
RGB Amplifiers
Selectable Gain Amplifiers
s _{Matched Inverting Amplifiers}
DESCRIPTION
The LT ^®1311 is a quad current-to-voltage converter de-
signed for the demanding requirements of photo diode
amplification. A new approach to current-to-voltage con-
version provides excellent DC and AC performance with-
out external DC trims or AC frequency compensation. The
LT1311 is ideal for converting multiple photo diode cur-
rents to voltages and for general purpose matched invert-
ing amplifier applications.
The LT1311 contains four current feedback amplifiers,
each with an internal 20k feedback resistor. A supply
bypass capacitor is the only external component required
to convert four signal currents to voltages. Unlike voltage
feedback-based current-to-voltage converters that oper-
ate with only a specified value of input capacitance, the
current feedback LT1311 settles cleanly with any input
capacitance up to 50pF. Only in the most demanding
applications will the LT1311 need to be mounted close to
the photo diodes.
, LTC and LT are registered trademarks of Linear Technology Corporation.
TYPICAL APPLICATION
Photo Diode Current-to-Voltage Converter
V_CC
10V
0.1µF
1 IN A
2
3 IN B
OUT A 14
–
+
13
+
OUT B 12
–
4 BIAS
11
5V
LT1311
5 IN C
6
7 IN D
–
OUT C 10
+
9
+
–
OUT D 8
1311 TA01
Transient Response
C_IN = 1pF
C_IN = 20pF
C_IN = 50pF
INPUT = 100µA STEP
V_S = ±5V
1311 TA02
1