Datasheet LT1970 (Analog Devices) - 8
| Hersteller | Analog Devices |
| Beschreibung | 500mA Power Op Amp with Adjustable Precision Current Limit |
| Seiten / Seite | 26 / 8 — pin FuncTions. VEE (Pins 1, 10, 11, 20, Package Base):. FILTER (Pin 5):. … |
| Dateiformat / Größe | PDF / 402 Kb |
| Dokumentensprache | Englisch |
pin FuncTions. VEE (Pins 1, 10, 11, 20, Package Base):. FILTER (Pin 5):. SENSE– (Pin 6):. V– (Pin 2):. VCC (Pin 7):. OUT (Pin 3):
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LT1970
pin FuncTions VEE (Pins 1, 10, 11, 20, Package Base):
Minus Supply
FILTER (Pin 5):
Current Sense Filter Pin. This pin is Voltage. VEE connects to the substrate of the integrated normally not used and should be left open or shorted to circuit die, and therefore must always be the most negative the SENSE– pin. The FILTER pin can be used to adapt the voltage applied to the part. Decouple VEE to ground with response time of the current sense amplifiers with a 1nF a low ESR capacitor. VEE may be a negative voltage or it to 100nF capacitor connected to the SENSE– input. An may equal ground potential. Any or all of the VEE pins may internal 1k resistor sets the filter time constant. be used. Unused VEE pins must remain open.
SENSE– (Pin 6):
Negative Current Sense Pin. This pin is
V– (Pin 2):
Output Stage Negative Supply. V– may equal normally connected to the load end of the external sense VEE or may be smaller in magnitude. Only output stage resistor. Sourcing current limit operation is activated when current flows out of V–, all other current flows out of VEE. the voltage VSENSE (VSENSE+ – VSENSE–) equals 1/10 of V– may be used to drive the base/gate of an external power the programming control voltage at VCSRC (Pin 13). Sink- device to boost the amplifier’s output current to levels above ing current limit operation is activated when the voltage the rated 500mA of the on-chip output devices. Unless VSENSE equals –1/10 of the programming control voltage used to drive boost transistors, V– should be decoupled at VCSNK (Pin 12). to ground with a low ESR capacitor.
VCC (Pin 7):
Positive Supply Voltage. All circuitry except
OUT (Pin 3):
Amplifier Output. The OUT pin provides the the output transistors draw power from VCC. Total sup- force function as part of a Kelvin sensed load connection. ply voltage from VCC to VEE must be between 3.5V and OUT is normally connected directly to an external load cur- 36V. VCC must always be greater than or equal to V+. VCC rent sense resistor and the SENSE+ pin. Amplifier feedback should always be decoupled to ground with a low ESR is directly connected to the load and the other end of the capacitor. current sense resistor. The load connection is also wired
–IN (Pin 8):
Inverting Input of Amplifier. –IN may be any directly to the SENSE– pin to monitor the load current. voltage from VEE – 0.3V to VEE + 36V. –IN and +IN remain The OUT pin is current limited to ±800mA typical. This high impedance at all times to prevent current flow into current limit protects the output transistor in the event the inputs when current limit mode is active. Care must that connections to the external sense resistor are be taken to insure that –IN or +IN can never go to a volt- opened or shorted which disables the precision current age below VEE – 0.3V even during transient conditions or limit function. damage to the circuit may result. A Schottky diode from
SENSE+ (Pin 4):
Positive Current Sense Pin. This lead is VEE to –IN can provide clamping if other elements in the normally connected to the driven end of the external sense circuit can allow –IN to go below VEE. resistor. Sourcing current limit operation is activated when
+IN (Pin 9):
Noninverting Input of Amplifier. +IN may be any the voltage VSENSE (VSENSE+ – VSENSE–) equals 1/10 of voltage from VEE – 0.3V to VEE + 36V. –IN and +IN remain the programming control voltage at VCSRC (Pin 13). Sink- high impedance at all times to prevent current flow into ing current limit operation is activated when the voltage the inputs when current limit mode is active. Care must VSENSE equals –1/10 of the programming control voltage be taken to insure that –IN or +IN can never go to a volt- at VCSNK (Pin 12). age below VEE – 0.3V even during transient conditions or damage to the circuit may result. A Schottky diode from VEE to +IN can provide clamping if other elements in the circuit can allow +IN to go below VEE. 1970fe 8 For more information www.linear.com/LT1970 Document Outline Description Typical Application Absolute Maximum Ratings Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Applications Information Package Description Related Parts
pin FuncTions VEE (Pins 1, 10, 11, 20, Package Base):
Minus Supply
FILTER (Pin 5):
Current Sense Filter Pin. This pin is Voltage. VEE connects to the substrate of the integrated normally not used and should be left open or shorted to circuit die, and therefore must always be the most negative the SENSE– pin. The FILTER pin can be used to adapt the voltage applied to the part. Decouple VEE to ground with response time of the current sense amplifiers with a 1nF a low ESR capacitor. VEE may be a negative voltage or it to 100nF capacitor connected to the SENSE– input. An may equal ground potential. Any or all of the VEE pins may internal 1k resistor sets the filter time constant. be used. Unused VEE pins must remain open.
SENSE– (Pin 6):
Negative Current Sense Pin. This pin is
V– (Pin 2):
Output Stage Negative Supply. V– may equal normally connected to the load end of the external sense VEE or may be smaller in magnitude. Only output stage resistor. Sourcing current limit operation is activated when current flows out of V–, all other current flows out of VEE. the voltage VSENSE (VSENSE+ – VSENSE–) equals 1/10 of V– may be used to drive the base/gate of an external power the programming control voltage at VCSRC (Pin 13). Sink- device to boost the amplifier’s output current to levels above ing current limit operation is activated when the voltage the rated 500mA of the on-chip output devices. Unless VSENSE equals –1/10 of the programming control voltage used to drive boost transistors, V– should be decoupled at VCSNK (Pin 12). to ground with a low ESR capacitor.
VCC (Pin 7):
Positive Supply Voltage. All circuitry except
OUT (Pin 3):
Amplifier Output. The OUT pin provides the the output transistors draw power from VCC. Total sup- force function as part of a Kelvin sensed load connection. ply voltage from VCC to VEE must be between 3.5V and OUT is normally connected directly to an external load cur- 36V. VCC must always be greater than or equal to V+. VCC rent sense resistor and the SENSE+ pin. Amplifier feedback should always be decoupled to ground with a low ESR is directly connected to the load and the other end of the capacitor. current sense resistor. The load connection is also wired
–IN (Pin 8):
Inverting Input of Amplifier. –IN may be any directly to the SENSE– pin to monitor the load current. voltage from VEE – 0.3V to VEE + 36V. –IN and +IN remain The OUT pin is current limited to ±800mA typical. This high impedance at all times to prevent current flow into current limit protects the output transistor in the event the inputs when current limit mode is active. Care must that connections to the external sense resistor are be taken to insure that –IN or +IN can never go to a volt- opened or shorted which disables the precision current age below VEE – 0.3V even during transient conditions or limit function. damage to the circuit may result. A Schottky diode from
SENSE+ (Pin 4):
Positive Current Sense Pin. This lead is VEE to –IN can provide clamping if other elements in the normally connected to the driven end of the external sense circuit can allow –IN to go below VEE. resistor. Sourcing current limit operation is activated when
+IN (Pin 9):
Noninverting Input of Amplifier. +IN may be any the voltage VSENSE (VSENSE+ – VSENSE–) equals 1/10 of voltage from VEE – 0.3V to VEE + 36V. –IN and +IN remain the programming control voltage at VCSRC (Pin 13). Sink- high impedance at all times to prevent current flow into ing current limit operation is activated when the voltage the inputs when current limit mode is active. Care must VSENSE equals –1/10 of the programming control voltage be taken to insure that –IN or +IN can never go to a volt- at VCSNK (Pin 12). age below VEE – 0.3V even during transient conditions or damage to the circuit may result. A Schottky diode from VEE to +IN can provide clamping if other elements in the circuit can allow +IN to go below VEE. 1970fe 8 For more information www.linear.com/LT1970 Document Outline Description Typical Application Absolute Maximum Ratings Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Applications Information Package Description Related Parts