Datasheet LT3020, LT3020-1.2, LT3020-1.5, LT3020-1.8 (Analog Devices) - 9
| Hersteller | Analog Devices |
| Beschreibung | 100mA, Low Voltage, Very Low Dropout Linear Regulator |
| Seiten / Seite | 16 / 9 — BLOCK DIAGRA. FIXED. VOUT. APPLICATIO S I FOR ATIO. Adjustable Operation. … |
| Dateiformat / Größe | PDF / 221 Kb |
| Dokumentensprache | Englisch |
BLOCK DIAGRA. FIXED. VOUT. APPLICATIO S I FOR ATIO. Adjustable Operation. Figure 1. Adjustable Operation
Modelllinie für dieses Datenblatt
- LT3020EDD#PBF LT3020EDD#PBF LT3020EDD#TRPBF LT3020EDD#TRPBF LT3020EDD-1.2#PBF LT3020EDD-1.2#PBF LT3020EDD-1.2#TRPBF LT3020EDD-1.2#TRPBF LT3020EDD-1.5#PBF LT3020EDD-1.5#PBF LT3020EDD-1.5#TRPBF LT3020EDD-1.5#TRPBF LT3020EDD-1.8#PBF LT3020EDD-1.8#PBF LT3020EDD-1.8#TRPBF LT3020EDD-1.8#TRPBF LT3020EMS8#PBF LT3020EMS8#PBF LT3020EMS8#TRPBF LT3020EMS8#TRPBF LT3020EMS8-1.2#PBF LT3020EMS8-1.2#PBF LT3020EMS8-1.2#TRPBF LT3020EMS8-1.2#TRPBF LT3020EMS8-1.5#PBF LT3020EMS8-1.5#PBF LT3020EMS8-1.5#TRPBF LT3020EMS8-1.5#TRPBF LT3020EMS8-1.8#PBF LT3020EMS8-1.8#PBF LT3020EMS8-1.8#TRPBF LT3020EMS8-1.8#TRPBF LT3020IDD#PBF LT3020IDD#PBF LT3020IDD#TRPBF LT3020IDD#TRPBF LT3020IDD-1.2#PBF LT3020IDD-1.2#PBF LT3020IDD-1.2#TRPBF LT3020IDD-1.2#TRPBF LT3020IDD-1.5#PBF LT3020IDD-1.5#PBF LT3020IDD-1.5#TRPBF LT3020IDD-1.5#TRPBF LT3020IDD-1.8#PBF LT3020IDD-1.8#PBF LT3020IDD-1.8#TRPBF LT3020IDD-1.8#TRPBF LT3020IMS8#PBF LT3020IMS8#PBF LT3020IMS8#TRPBF LT3020IMS8#TRPBF LT3020IMS8-1.2#PBF LT3020IMS8-1.2#PBF LT3020IMS8-1.2#TRPBF LT3020IMS8-1.2#TRPBF LT3020IMS8-1.5#PBF LT3020IMS8-1.5#PBF LT3020IMS8-1.5#TRPBF LT3020IMS8-1.5#TRPBF LT3020IMS8-1.8#PBF LT3020IMS8-1.8#PBF LT3020IMS8-1.8#TRPBF LT3020IMS8-1.8#TRPBF
Textversion des Dokuments
LT3020/LT3020-1.2/ LT3020-1.5/LT3020-1.8
W BLOCK DIAGRA
IN (7, 8) SHDN THERMAL R3 SHUTDOWN (5) SHUTDOWN D1 – Q3 CURRENT ERROR AMP Q1 + GAIN 200mV BIAS CURRENT AND D2 OUT REFERENCE (1, 2) GENERATOR OUT SENSE 212mV – (3) NO-LOAD Q2 RECOVERY + R2 25k ADJ (3) R1
FIXED
NOTE:
VOUT R1 R2
FOR LT3020 ADJUST PIN 3 IS CONNECTED TO 1.2V 20k 100k THE ADJUST PIN, R1 AND R2 ARE EXTERNAL. GND 1.5V 20k 130k FOR LT3020-1.X PIN 3 IS CONNECTED TO THE (4,9) 1.8V 20k 160k 3020 BD OUTPUT SENSE PIN, R1 AND R2 ARE INTERNAL.
U U W U APPLICATIO S I FOR ATIO
The LT3020 is a very low dropout linear regulator capable current in R2 is the current in R1 minus the ADJ pin bias of 0.9V input supply operation. Devices supply 100mA of current. The ADJ pin bias current of 20nA flows out of the output current and dropout voltage is typically 150mV. pin. Use the formula in Figure 1 to calculate output voltage. Quiescent current is typically 120µA and drops to 3µA in An R1 value of 20k sets the resistor divider current to shutdown. The LT3020 incorporates several protection 10µA. Note that in shutdown the output is turned off and features, making it ideal for use in battery-powered sys- the divider current is zero. Curves of ADJ Pin Voltage vs tems. The device protects itself against reverse-input and Temperature and ADJ Pin Bias Current vs Temperature reverse-output voltages. In battery backup applications appear in the Typical Performance Characteristics section. where the output is held up by a backup battery when the Specifications for output voltages greater than 200mV are input is pulled to ground, the LT3020 acts as if a diode is proportional to the ratio of desired output voltage to in series with its output which prevents reverse current 200mV; (V flow. In dual supply applications where the regulator load OUT/200mV). For example, load regulation for is returned to a negative supply, the output can be pulled below ground by as much as 10V without affecting start- IN OUT VOUT + VIN LT3020-ADJ R2 up or normal operation. SHDN ADJ GND R1
Adjustable Operation
3020 F01 The LT3020’s output voltage range is 0.2V to 9.5V. Figure R2 VOUT = 200mV 1 + – I R1 ADJ (R2) ( ) 1 shows that the output voltage is set by the ratio of two VADJ = 200mV external resistors. The device regulates the output to IADJ = 20nA AT 25°C OUTPUT RANGE = 0.2V TO 9.5V maintain the ADJ pin voltage at 200mV referenced to ground. The current in R1 equals 200mV/R1 and the
Figure 1. Adjustable Operation
3020fc 9
W BLOCK DIAGRA
IN (7, 8) SHDN THERMAL R3 SHUTDOWN (5) SHUTDOWN D1 – Q3 CURRENT ERROR AMP Q1 + GAIN 200mV BIAS CURRENT AND D2 OUT REFERENCE (1, 2) GENERATOR OUT SENSE 212mV – (3) NO-LOAD Q2 RECOVERY + R2 25k ADJ (3) R1
FIXED
NOTE:
VOUT R1 R2
FOR LT3020 ADJUST PIN 3 IS CONNECTED TO 1.2V 20k 100k THE ADJUST PIN, R1 AND R2 ARE EXTERNAL. GND 1.5V 20k 130k FOR LT3020-1.X PIN 3 IS CONNECTED TO THE (4,9) 1.8V 20k 160k 3020 BD OUTPUT SENSE PIN, R1 AND R2 ARE INTERNAL.
U U W U APPLICATIO S I FOR ATIO
The LT3020 is a very low dropout linear regulator capable current in R2 is the current in R1 minus the ADJ pin bias of 0.9V input supply operation. Devices supply 100mA of current. The ADJ pin bias current of 20nA flows out of the output current and dropout voltage is typically 150mV. pin. Use the formula in Figure 1 to calculate output voltage. Quiescent current is typically 120µA and drops to 3µA in An R1 value of 20k sets the resistor divider current to shutdown. The LT3020 incorporates several protection 10µA. Note that in shutdown the output is turned off and features, making it ideal for use in battery-powered sys- the divider current is zero. Curves of ADJ Pin Voltage vs tems. The device protects itself against reverse-input and Temperature and ADJ Pin Bias Current vs Temperature reverse-output voltages. In battery backup applications appear in the Typical Performance Characteristics section. where the output is held up by a backup battery when the Specifications for output voltages greater than 200mV are input is pulled to ground, the LT3020 acts as if a diode is proportional to the ratio of desired output voltage to in series with its output which prevents reverse current 200mV; (V flow. In dual supply applications where the regulator load OUT/200mV). For example, load regulation for is returned to a negative supply, the output can be pulled below ground by as much as 10V without affecting start- IN OUT VOUT + VIN LT3020-ADJ R2 up or normal operation. SHDN ADJ GND R1
Adjustable Operation
3020 F01 The LT3020’s output voltage range is 0.2V to 9.5V. Figure R2 VOUT = 200mV 1 + – I R1 ADJ (R2) ( ) 1 shows that the output voltage is set by the ratio of two VADJ = 200mV external resistors. The device regulates the output to IADJ = 20nA AT 25°C OUTPUT RANGE = 0.2V TO 9.5V maintain the ADJ pin voltage at 200mV referenced to ground. The current in R1 equals 200mV/R1 and the
Figure 1. Adjustable Operation
3020fc 9