DatasheetLT6236, LT6237, LT6238 (Analog Devices) - 26
| Manufacturer | Analog Devices |
| Description | Rail-to-Rail Output 215MHz, 1.1nV/√Hz Op Amp/SAR ADC Driver |
| Pages / Page | 26 / 26 — Typical applicaTion. Low Power Avalanche Photodiode Transimpedance … |
| File Format / Size | PDF / 1.6 Mb |
| Document Language | English |
Typical applicaTion. Low Power Avalanche Photodiode Transimpedance Amplifier. Photodiode Amplifier Time Domain Response
Model Line for this Datasheet
- LT6236CS6#PBF LT6236CS6#TRMPBF LT6236CS6#TRPBF LT6236HS6#PBF LT6236HS6#TRMPBF LT6236HS6#TRPBF LT6236IS6#PBF LT6236IS6#TRMPBF LT6236IS6#TRPBF
Text Version of Document
LT6236/LT6237/LT6238
Typical applicaTion
The LT6236 is configured as a transimpedance amplifier IPD which flows into the amplifier circuit. The amplifier with an I-to-V conversion gain of 1.5kΩ set by R1. The output falls negative to maintain balance at its inputs. LT6236 is ideally suited to this application because of its The transfer function is therefore VOUT = –IPD • 1.5k. C1 low input offset voltage and current, and its low noise. ensures stability and good settling characteristics. Output This is because the 1.5k resistor has an inherent thermal offset was measured at 280µV, so low in part because R2 noise of 5nV/√Hz or 3.4pA/√Hz at room temperature, while serves to cancel the DC effects of bias current. Output the LT6236 contributes only 1.1nV/√Hz and 2.4pA/√Hz. noise was measured at 1.1mVP–P on a 100MHz measure- So, with respect to both voltage and current noises, the ment bandwidth, with C2 shunting R2’s thermal noise. As LT6236 is actually quieter than the gain resistor. The shown in the scope photo, the rise time is 17ns, indicating circuit uses an avalanche photodiode with the cathode a signal bandwidth of 20MHz. biased to approximately 200V. When light is incident on the photodiode, it induces a current
Low Power Avalanche Photodiode Transimpedance Amplifier Photodiode Amplifier Time Domain Response IS = 3.3mA
≈200V BIAS C1 4.7pF ADVANCED PHOTONIX 012-70-62-541 /DIV WWW.ADVANCEDPHOTONIX.COM R1 30mV 1.5k – 5V R2 LT6236 1.5k + –5V 50ns/DIV 62367 TA07 ENABLE C2 62367 TA06 0.1µF OUTPUT OFFSET = 500µV TYPICAL BANDWIDTH = 20MHz OUTPUT NOISE = 1.1mVP-P (100MHz MEASUREMENT BW)
relaTeD parTs PART NUMBER DESCRIPTION COMMENTS OPERATIONAL AMPLIFIERS
LT6230/LT6231/LT6232 Single, Dual, Quad Low Noise, Rail-to-Rail Output. 1.1nV/√Hz LT6350 Low Noise, Single-Ended to Differential Converter/ADC Driver 4.8mA, –97dBc Distortion at 100kHz, 4VP-P Output LTC6246/LTC6247/LTC6248 Single/Dual/Quad 180MHz Rail-to-Rail Low Power Op Amps 1mA/Amplifier, 4.2nV/√Hz LTC6360 1GHz Very Low Noise Single-Ended SAR ADC Driver with HD2 = –103dBc and HD3 = –109dBc for 4VP-P Output at 40kHz True Zero Output
ADCs
LTC2389-18 Low Power 18-Bit SAR ADC 2.5Msps LTC2389-16 Low Power 16-Bit SAR ADC 2.5Msps LTC2379-18 Low Power 18-Bit SAR ADC 1.6Msps LTC2378-18 1Msps LTC2377-18 500ksps LTC2376-18 250ksps 623637fb 26 LT 0914 REV B • PRINTED IN USA Linear Technology Corporation 1630 McCarthy Blvd., Milpitas, CA 95 F0o3r 5m-o 7 r4e in 17 formation www.linear.com/LT6236 (408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com/LT6236 LINEAR TECHNOLOGY CORPORATION 2012
Typical applicaTion
The LT6236 is configured as a transimpedance amplifier IPD which flows into the amplifier circuit. The amplifier with an I-to-V conversion gain of 1.5kΩ set by R1. The output falls negative to maintain balance at its inputs. LT6236 is ideally suited to this application because of its The transfer function is therefore VOUT = –IPD • 1.5k. C1 low input offset voltage and current, and its low noise. ensures stability and good settling characteristics. Output This is because the 1.5k resistor has an inherent thermal offset was measured at 280µV, so low in part because R2 noise of 5nV/√Hz or 3.4pA/√Hz at room temperature, while serves to cancel the DC effects of bias current. Output the LT6236 contributes only 1.1nV/√Hz and 2.4pA/√Hz. noise was measured at 1.1mVP–P on a 100MHz measure- So, with respect to both voltage and current noises, the ment bandwidth, with C2 shunting R2’s thermal noise. As LT6236 is actually quieter than the gain resistor. The shown in the scope photo, the rise time is 17ns, indicating circuit uses an avalanche photodiode with the cathode a signal bandwidth of 20MHz. biased to approximately 200V. When light is incident on the photodiode, it induces a current
Low Power Avalanche Photodiode Transimpedance Amplifier Photodiode Amplifier Time Domain Response IS = 3.3mA
≈200V BIAS C1 4.7pF ADVANCED PHOTONIX 012-70-62-541 /DIV WWW.ADVANCEDPHOTONIX.COM R1 30mV 1.5k – 5V R2 LT6236 1.5k + –5V 50ns/DIV 62367 TA07 ENABLE C2 62367 TA06 0.1µF OUTPUT OFFSET = 500µV TYPICAL BANDWIDTH = 20MHz OUTPUT NOISE = 1.1mVP-P (100MHz MEASUREMENT BW)
relaTeD parTs PART NUMBER DESCRIPTION COMMENTS OPERATIONAL AMPLIFIERS
LT6230/LT6231/LT6232 Single, Dual, Quad Low Noise, Rail-to-Rail Output. 1.1nV/√Hz LT6350 Low Noise, Single-Ended to Differential Converter/ADC Driver 4.8mA, –97dBc Distortion at 100kHz, 4VP-P Output LTC6246/LTC6247/LTC6248 Single/Dual/Quad 180MHz Rail-to-Rail Low Power Op Amps 1mA/Amplifier, 4.2nV/√Hz LTC6360 1GHz Very Low Noise Single-Ended SAR ADC Driver with HD2 = –103dBc and HD3 = –109dBc for 4VP-P Output at 40kHz True Zero Output
ADCs
LTC2389-18 Low Power 18-Bit SAR ADC 2.5Msps LTC2389-16 Low Power 16-Bit SAR ADC 2.5Msps LTC2379-18 Low Power 18-Bit SAR ADC 1.6Msps LTC2378-18 1Msps LTC2377-18 500ksps LTC2376-18 250ksps 623637fb 26 LT 0914 REV B • PRINTED IN USA Linear Technology Corporation 1630 McCarthy Blvd., Milpitas, CA 95 F0o3r 5m-o 7 r4e in 17 formation www.linear.com/LT6236 (408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com/LT6236 LINEAR TECHNOLOGY CORPORATION 2012