Datasheet LT1970A (Analog Devices) - 10
| Manufacturer | Analog Devices |
| Description | 500mA Power Op Amp with Adjustable Precision Current Limit |
| Pages / Page | 24 / 10 — block DiagraM anD TesT circuiT. applicaTions inForMaTion. CIRCUIT … |
| File Format / Size | PDF / 385 Kb |
| Document Language | English |
block DiagraM anD TesT circuiT. applicaTions inForMaTion. CIRCUIT DESCRIPTION. Current Limit Amplifiers
Model Line for this Datasheet
Text Version of Document
LT1970A
block DiagraM anD TesT circuiT
RF VCC 1k 7 V+ 19 15V +IN 9 + Q1 + V OUT IN – GM1 1× 3 –IN 8 – Q2 RG 1k 10k ISNK 17 10k – ISRC 16 D1 10k I + R SNK CS TSD VSNK – 15V 18 + 1Ω SENSE+ 4 ENABLE FILTER + 15 ENABLE VSRC 5 – VC SENSE– SNK 5V 12 VCSNK – 6 RFIL D2 1k VC R SRC LOAD 13 I VC SRC V– SRC + 1k 2 COMMON V 14 EE –15V 1, 10, 11, 20 1970ATC
applicaTions inForMaTion
The LT1970A power op amp with precision controllable a conventional manner. The output stage includes current current limit is a flexible voltage and current source limiting at ±800mA to protect against fault conditions. module. The drawing on the front page of this data sheet The input stage has high differential breakdown of 36V is representative of the basic application of the circuit, minimum between –IN and +IN. No current will flow at however many alternate uses are possible with proper the inputs when differential input voltage is present. This understanding of the sub circuit capabilities. feature is important when the precision current sense amplifiers “ISINK” and “ISRC” become active.
CIRCUIT DESCRIPTION Current Limit Amplifiers Main Operational Amplifier
Amplifier stages “ISINK” and “ISRC” are very high transcon- Sub circuit block GM1, the 1X unity-gain current buf- ductance amplifier stages with independently controlled fer and output transistors Q1 and Q2 form a standard offset voltages. These amplifiers monitor the voltage operational amplifier. This amplifier has ±500mA current between input pins SENSE+ and SENSE– which usually output capability and a 3.6MHz gain-bandwidth product. sense the voltage across a small external current sense Most applications of the LT1970A will use this op amp resistor. The transconductance amplifiers outputs con- in the main signal path. All conventional op amp circuit nect to the same high impedance node as the main input configurations are supported. Inverting, noninverting, filter, stage GM1 amplifier. Small voltage differences between summation or nonlinear circuits may be implemented in SENSE+ and SENSE–, smaller than the user set VCSNK/10 1970afc 10 For more information www.linear.com/LT1970A Document Outline Features Applications Description Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram And Test Circuit Applications Information Package Description Applications Information Related Parts
block DiagraM anD TesT circuiT
RF VCC 1k 7 V+ 19 15V +IN 9 + Q1 + V OUT IN – GM1 1× 3 –IN 8 – Q2 RG 1k 10k ISNK 17 10k – ISRC 16 D1 10k I + R SNK CS TSD VSNK – 15V 18 + 1Ω SENSE+ 4 ENABLE FILTER + 15 ENABLE VSRC 5 – VC SENSE– SNK 5V 12 VCSNK – 6 RFIL D2 1k VC R SRC LOAD 13 I VC SRC V– SRC + 1k 2 COMMON V 14 EE –15V 1, 10, 11, 20 1970ATC
applicaTions inForMaTion
The LT1970A power op amp with precision controllable a conventional manner. The output stage includes current current limit is a flexible voltage and current source limiting at ±800mA to protect against fault conditions. module. The drawing on the front page of this data sheet The input stage has high differential breakdown of 36V is representative of the basic application of the circuit, minimum between –IN and +IN. No current will flow at however many alternate uses are possible with proper the inputs when differential input voltage is present. This understanding of the sub circuit capabilities. feature is important when the precision current sense amplifiers “ISINK” and “ISRC” become active.
CIRCUIT DESCRIPTION Current Limit Amplifiers Main Operational Amplifier
Amplifier stages “ISINK” and “ISRC” are very high transcon- Sub circuit block GM1, the 1X unity-gain current buf- ductance amplifier stages with independently controlled fer and output transistors Q1 and Q2 form a standard offset voltages. These amplifiers monitor the voltage operational amplifier. This amplifier has ±500mA current between input pins SENSE+ and SENSE– which usually output capability and a 3.6MHz gain-bandwidth product. sense the voltage across a small external current sense Most applications of the LT1970A will use this op amp resistor. The transconductance amplifiers outputs con- in the main signal path. All conventional op amp circuit nect to the same high impedance node as the main input configurations are supported. Inverting, noninverting, filter, stage GM1 amplifier. Small voltage differences between summation or nonlinear circuits may be implemented in SENSE+ and SENSE–, smaller than the user set VCSNK/10 1970afc 10 For more information www.linear.com/LT1970A Document Outline Features Applications Description Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram And Test Circuit Applications Information Package Description Applications Information Related Parts
