LT6230CS6-10 LINER [Linear Technology], LT6230CS6-10 Datasheet - Page 24

• Manufacturer Part Number: LT6230CS6-10
• Description: 215MHz, Rail-to-Rail Output, 1.1nV/ root Hz, 3.5mA Op Amp Family
• Manufacturer: LINER [Linear Technology]

LT6230/LT6230-10/
LT6231/LT6232
The LT6230 is applied as a transimpedance amplifier with
an I-to-V conversion gain of 1.5k set by R1. The LT6230
is ideally suited to this application because of its low input
offset voltage and current, and its low noise. This is be-
cause the 1.5k resistor has an inherent thermal noise of
5nV/ Hz or 3.4pA/ Hz at room temperature, while the
LT6230 contributes only 1.1nV and 2.4pA / Hz. So, with
respect to both voltage and current noises, the LT6230 is
actually quieter than the gain resistor.
The circuit uses an avalanche photodiode with the cathode
biased to approximately 200V. When light is incident on
RELATED PARTS
24
TYPICAL APPLICATIO S
PART NUMBER
LT1028
LT1677
LT1806/LT1807
LT6200/LT6201
LT6202/LT6203/LT6204
Low Power Avalanche Photodiode Transimpedance Amplifier
WWW.ADVANCEDPHOTONIX.COM
ADVANCED PHOTONIX
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
[phone] FAX: [phone]
012-70-62-541
OUTPUT OFFSET = 500 V TYPICAL
BANDWIDTH = 20MHz
OUTPUT NOISE = 1.1mV
200V BIAS
DESCRIPTION
Single, Ultra Low Noise 50MHz Op Amp
Single, Low Noise Rail-to-Rail Amplifier
Single/Dual, Low Noise 325MHz Rail-to-Rail Amplifier
Single/Dual, Low Noise 165MHz
Single/Dual/Quad, Low Noise, Rail-to-Rail Amplifier
0.1 F
1.5k
I
R2
C2
S
= 3.3mA
P–P
(100MHz MEASUREMENT BW)
–
+
U
LT6230
ENABLE
4.7pF
1.5k
R1
C1
www.linear.com
–5V
5V
623012 TA02a
the photodiode, it induces a current I
the amplifier circuit. The amplifier output falls negative to
maintain balance at its inputs. The transfer function is
therefore V
settling characteristics. Output offset was measured
at 280 V, so low in part because R2 serves to cancel the
DC effects of bias current. Output noise was measured at
1.1mV
shunting R2’s thermal noise. As shown in the scope
photo, the rise time is 17ns, indicating a signal bandwidth
of 20MHz.
P–P
COMMENTS
0.85nV/ Hz
3V Operation, 2.5mA, 4.5nV/ Hz, 60 V Max V
2.5V Operation, 550 V Max V
0.95nV Hz, Rail-to-Rail Input and Output
1.9nV/ Hz, 3mA Max, 100MHz Gain Bandwidth
Photodiode Amplifier Time Domain Response
on a 100MHz measurement bandwidth, with C2
OUT
= –I
PD
• 1.5k. C1 ensures stability and good
50ns/DIV
LINEAR TECHNOLOGY CORPORATION 2003
OS
LT/TP 0304 1K REV A • PRINTED IN USA
, 3.5nV/ Hz
PD
623012 TA02b
which flows into
OS
sn623012 623012fas