Datasheet

ManualsBrandsLinear Technology ManualsIntegrated Circuits (ICs)LDO Voltage Regulator 200mA SOT-23

LT1964

1964f

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Battery-Powered Instruments

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Low Noise Regulator for Noise-Sensitive

Instrumentation

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Negative Complement to LT1761 Family of

Positive LDOs

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Low Profile (1mm) ThinSOT

Package

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Low Noise: 30µV

RMS

(10Hz to 100kHz)

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Low Quiescent Current: 30µA

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Low Dropout Voltage: 340mV

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Output Current: 200mA

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Fixed Output Voltage: –5V

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Adjustable Output from –1.22V to –20V

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Positive or Negative Shutdown Logic

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3µA Quiescent Current in Shutdown

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Stable with 1µF Output Capacitor

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Stable with Aluminum, Tantalum, or Ceramic

Capacitors

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Thermal Limiting

200mA, Low Noise,

Low Dropout Negative

Micropower Regulator in ThinSOT

The LT

1964 is a micropower low noise, low dropout

negative regulator. The device is capable of supplying

200mA of output current with a dropout voltage of 340mV.

Low quiescent current (30µA operating and 3µA shut-

down) makes the LT1964 an excellent choice for battery-

powered applications. Quiescent current is well controlled

in dropout.

Other features of the LT1964 include low output noise.

With the addition of an external 0.01µF bypass capacitor,

output noise is reduced to 30µV

RMS

over a 10Hz to 100kHz

bandwidth. The LT1964 is capable of operating with small

capacitors and is stable with output capacitors as low as

1µF. Small ceramic capacitors can be used without the

necessary addition of ESR as is common with other

regulators. Internal protection circuitry includes reverse

output protection, current limiting, and thermal limiting.

The device is available with a fixed output voltage of –5V

and as an adjustable device with a –1.22V reference

voltage. The LT1964 regulators are available in a low

profile (1mm) ThinSOT package.

, LTC and LT are registered trademarks of Linear Technology Corporation.

1964 TA01a

GND

SHDN BYP

OUT

LT1964-5

1µF

10µF

0.01µF

–5.4V

TO –20V

–5V AT 200mA

30µV

RMS

NOISE

–5V Low Noise Regulator

10Hz to 100kHz Output Noise

OUT

100µV/DIV

1ms/DIV

1964 TA01b

30µV

RMS

ThinSOT is a trademark of Linear Technology Corporation.

APPLICATIO S

FEATURES

TYPICAL APPLICATIO

DESCRIPTIO

Summary of content (14 pages)

PAGE 1
LT1964 200mA, Low Noise, Low Dropout Negative Micropower Regulator in ThinSOT U DESCRIPTIO FEATURES ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ Low Profile (1mm) ThinSOTTM Package Low Noise: 30µVRMS (10Hz to 100kHz) Low Quiescent Current: 30µA Low Dropout Voltage: 340mV Output Current: 200mA Fixed Output Voltage: –5V Adjustable Output from –1.
PAGE 2
LT1964 W W U W ABSOLUTE AXI U RATI GS (Note 1) IN Pin Voltage ........................................................ ±20V OUT Pin Voltage (Note 11) .................................... ±20V OUT to IN Differential Voltage (Note 11) ....... –0.5V, 20V ADJ Pin Voltage (with Respect to IN Pin) (Note 11) ........... –0.5V, 20V BYP Pin Voltage (with Respect to IN Pin) ................................... ±20V SHDN Pin Voltage (with Respect to IN Pin) (Note 11) ........... –0.
PAGE 3
LT1964 ELECTRICAL CHARACTERISTICS The ● denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C.
PAGE 4
LT1964 U W TYPICAL PERFOR A CE CHARACTERISTICS Guaranteed Dropout Voltage 500 450 450 400 400 TJ = 125°C 350 300 250 TJ = 25°C 200 150 Dropout Voltage 500 = TEST POINT 450 TJ ≤ 125°C DROPOUT VOLTAGE (mV) 500 DROPOUT VOLTAGE (mV) DROPOUT VOLTAGE (mV) Typical Dropout Voltage 350 300 250 TJ ≤ 25°C 200 150 250 IL = –100mA 200 IL = –50mA 150 100 50 50 50 0 –40 –80 –120 –160 OUTPUT CURRENT (mA) 0 –200 0 –40 –80 –120 –160 OUTPUT CURRENT (mA) –20 –15 100 125 –1.
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LT1964 U W TYPICAL PERFOR A CE CHARACTERISTICS LT1964-BYP, LT1964-SD GND Pin Current –3.0 –4.0 TJ = 25°C; VSHDN = VIN; *FOR VOUT = –1.22V 2.5 VIN = VOUT(NOMINAL) – 1V 2.0 RL = 12.2Ω IL = –100mA* –1.5 –1.0 RL = 24.4Ω IL = –50mA* –0.5 RL = 122Ω IL = –10mA* 0 –3.0 –2.5 TJ = 25°C –2.0 TJ = 125°C –1.5 –1.0 0 –1 –2 –3 –4 –5 –6 –7 –8 –9 –10 INPUT VOLTAGE (V) 0 –1.
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LT1964 U W TYPICAL PERFOR A CE CHARACTERISTICS LT1964-BYP Minimum Input Voltage Input Ripple Rejection 56 54 52 50 48 46 44 –50 –25 0 25 50 75 TEMPERATURE (°C) 100 –3.0 –3.0 –2.5 –2.5 –2.0 IL = –200mA –1.5 IL = –1mA –1.0 NOTE: THE MINIMUM INPUT VOLTAGE ACCOUNTS FOR THE OPERATING THRESHOLD OF THE SHDN PIN WHICH IS TIED TO THE IN PIN INTERNALLY –0.
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LT1964 U W TYPICAL PERFOR A CE CHARACTERISTICS LT1964-5, 10Hz to 100kHz Output Noise, CBYP = 1000pF VOUT (100µV/DIV) VOUT (100µV/DIV) LT1964-5, 10Hz to 100kHz Output Noise, CBYP = 0.01µF COUT = 10µF ILOAD = – 200mA 1ms/DIV COUT = 10µF ILOAD = – 200mA 1964 G28.tif 0.1 OUTPUT VOLTAGE DEVIATION (V) VIN = –6V CIN = 10µF COUT = 10µF 0.2 0 –0.1 –0.2 0 –100 –200 0 400 800 1200 TIME (µs) 1600 1964 G29.tif LT1964-5, Transient Response, CBYP = 0.
PAGE 8
LT1964 U U U PI FU CTIO S collector logic with a pull-up resistor. The pull-up resistor is required to supply the pull-up current of the open collector gate, normally several microamperes, and the SHDN pin current, typically 3µA out of the pin (for negative logic) or 6µA into the pin (for positive logic). If unused, the SHDN pin must be connected to VIN. The device will be shut down if the SHDN pin is open circuit. For the LT1964-BYP, the SHDN pin is internally connected to VIN.
PAGE 9
LT1964 U W U U APPLICATIO S I FOR ATIO Output Capacitance and Transient Response R1 GND + ADJ VIN LT1964 IN R2 OUT VOUT 1964 F01 VOUT = –1.22V(1 + R2 ) – (IADJ)(R2) R1 VADJ = –1.22V IADJ = 30nA AT 25°C OUTPUT RANGE = –1.22V TO –20V Figure 1. Adjustable Operation Bypass Capacitance and Low Noise Performance The LT1964 may be used with the addition of a bypass capacitor from VOUT to the BYP pin to lower output voltage noise. A good quality low leakage capacitor is recommended.
PAGE 10
LT1964 U U W U APPLICATIO S I FOR ATIO 20 Thermal Considerations BOTH CAPACITORS ARE 16V, 1210 CASE SIZE, 10µF The power handling capability of the device will be limited by the maximum rated junction temperature (125°C). The power dissipated by the device will be made up of two components: CHANGE IN VALUE (%) 0 X5R –20 –40 1.
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LT1964 U U W U APPLICATIO S I FOR ATIO Calculating Junction Temperature Example: Given an output voltage of –5V, an input voltage range of –6V to –8V, an output current range of 0mA to –100mA, and a maximum ambient temperature of 50°C, what will the maximum junction temperature be? The power dissipated by the device will be equal to: IOUT(MAX) • (VIN(MAX) – VOUT) + (IGND • VIN(MAX)) where, IOUT(MAX) = –100mA VIN(MAX) = –8V IGND at (IOUT = –100mA, VIN = –8V) = –2mA so, P = –100mA • (–8V + 5V) + (–2mA •
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LT1964 U PACKAGE DESCRIPTIO S5 Package 5-Lead Plastic TSOT-23 (Reference LTC DWG # 05-08-1635) 0.62 MAX 0.95 REF 2.90 BSC (NOTE 4) 1.22 REF 1.4 MIN 3.85 MAX 2.62 REF 2.80 BSC 1.50 – 1.75 (NOTE 4) PIN ONE RECOMMENDED SOLDER PAD LAYOUT PER IPC CALCULATOR 0.30 – 0.45 TYP 5 PLCS (NOTE 3) 0.95 BSC 0.80 – 0.90 0.20 BSC 0.01 – 0.10 1.00 MAX DATUM ‘A’ 0.30 – 0.50 REF 1.90 BSC 0.09 – 0.20 (NOTE 3) NOTE: 1. DIMENSIONS ARE IN MILLIMETERS 2. DRAWING NOT TO SCALE 3.
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PAGE 14
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