LTC1261CS8-4 Linear Technology, LTC1261CS8-4 Datasheet
LTC1261CS8-4
Specifications of LTC1261CS8-4
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LTC1261CS8-4 Summary of contents
Page 1
... An on-chip resistor string allows the LTC1261CS to be configured for output volt- ages of – 3.5V, – 4V, – 4.5V or – 5V with no external components. The LTC1261CS8 is optimized for applica- tions which use higher supply or which require low output voltages. It requires a single external 0.1 F capacitor and provides adjustable and fixed output voltage options in 8-pin SO packages ...
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... REG CC = 1.24V ADJ = V SHDN CC = 15mA U W ORDER PART TOP VIEW NUMBER 1 8 SHDN LTC1261CS8 2 7 REG LTC1261CS8 OUT LTC1261CS8-4.5 ADJ (COMP PART MARKING S8 PACKAGE 8-LEAD PLASTIC SO 1261 *FOR FIXED VERSIONS 12614 = 150 C, = 150 C/W JA 126145 ORDER PART TOP VIEW NUMBER SHDN ...
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... F unless otherwise specified – (Note 7) MIN TYP MAX MIN TYP MAX – (Note 7) MIN TYP MAX MIN TYP MAX – + and C2 floating. For the LTC1261CS8 in doubler mode, + – there are no C2 pins. – 12V. CC UNITS % UNITS UNITS UNITS ...
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LTC1261 W U TYPICAL PERFORMANCE CHARACTERISTICS Output Voltage vs Output Current –3 –3.6 A –3.7 –3 –3.9 DOUBLER MODE –4 3.3V CC –4.1 TRIPLER MODE –4.2 –4.3 –4.4 –4.5 0 ...
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... PIN FUNCTIONS Pin numbers are shown as (LTC1261CS/LTC1261CS8). NC (Pin 1/NA): No Internal Connection (Pin 2/ Pin 2): C1 Positive Input. Connect a 0 – capacitor between C1 and C1 . With the LTC1261CS in doubler mode, connect a 0.1 F capacitor from C1 – – C1 (Pin 3/Pin 3): C1 Negative Input. Connect a 0 – ...
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... S capacitor to invert the input supply voltage, and the output voltage is stored on the output bypass capacitor between switch cycles. The LTC1261CS8 is always configured in doubler mode and has only one pair of flying capacitor pins (Figure 1a). The LTC1261CS can be configured in doubler mode by connecting a single flying capacitor + – ...
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U U APPLICATIONS INFORMATION CLK 550kHz COMP 1 – V REF The output voltage is monitored by COMP1 which com- pares a divided replica of the output at ADJ (COMP for fixed output parts) to the ...
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LTC1261 U U APPLICATIONS INFORMATION OUTPUT RIPPLE Output ripple in the LTC1261 comes from two sources; voltage droop at the output capacitor between clocks and frequency response of the regulation loop. Voltage droop is easy to calculate. With a typical ...
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... U U APPLICATIONS INFORMATION OUT 0.1 F LTC1261CS8 – C1 COMP + GND 100pF 4 Figure 4. Output Filter Cuts Ripple Below 3mV CAPACITOR SELECTION Capacitor Sizing The performance of the LTC1261 can be affected by the capacitors it is connected to. The LTC1261 requires by- pass capacitors to ground for both the V The input capacitor provides most of LTC1261’s supply current while it is charging the flying capacitors ...
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... The LTC1261 uses a positive OUT , not a negative reference OUT 6 (4*) GND R1 LTC1261 10 (5*) ADJ –1.24V OUT OUT R2 *LTC1261CS8 LTC1261 • F06 Figure 6. External Resistor Connections ...
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... The LTC1261 can be internally configured with nonstand- ard fixed output voltages. Contact the Linear Technology Marketing Department for details. N 3.3V Input, – 4.5V Output GaAs FET Bias Generator ...
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LTC1261 U TYPICAL APPLICATIONS V BAT SHUTDOWN 0 8.4V BAT (7 NiCd CELLS) SHUTDOWN 1 F 0.1 F 1mV Ripple, 5V Input, – 4V Output GaAs FET Bias Generator V BAT SHUTDOWN 5V 1 ...
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U TYPICAL APPLICATIONS High Supply Voltage, – 5V Output GaAs FET Bias Generator 8V V 12V BAT SHUTDOWN 0.1 F 0.1 F Low Output Voltage Generator 100pF ADJ 0.1 F ...
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... LTC1261 U TYPICAL APPLICATIONS This circuit uses the LTC1261CS8 to generate a – 1.24V output at 20mA. Attached to this output is a 312 resistor to make the current/voltage conversion. 4mA through 312 generates 1.24V, giving a net 0V output. 20mA through 312 gives 6.24V across the resistor, giving a net 5V output ...
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... FLASH SHALL NOT EXCEED 0.010" (0.254mm) PER SIDE Information furnished by Linear Technology Corporation is believed to be accurate and reliable. However, no responsibility is assumed for its use. Linear Technology Corporation makes no represen- tation that the interconnection of its circuits as described herein will not infringe on existing patent rights. ...
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... GaAs FET Bias with Linear Regulator 1mV Ripple GaAs FET Bias 0.4V Dropout Voltage at 150mA, Low Noise, Switched Capacitor Regulated Voltage Inverter –0.5V BIAS 5.5% GaAs TRANSMITTER 3.3 F LTC1261 • TA08 1261fa LT/TP 0198 REV A 4K • PRINTED IN USA LINEAR TECHNOLOGY CORPORATION 1994 ...