LTC1261L Linear Technology, LTC1261L Datasheet
LTC1261L
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LTC1261L Summary of contents
Page 1
... The LTC1261L includes an open-drain REG output that pulls low when the output is within 5% of the set value. Quiescent current is typically 650 A when operating and shutdown. The LTC1261L is available in 8-pin MSOP and SO pack- ages. , LTC and LT are registered trademarks of Linear Technology Corporation. 5V ...
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... V CC OUT OUT 5mA – 4.5V (LTC1261L) CC OUT OUT 10mA – 4V (LTC1261L-4) CC OUT OUT 5mA – 4.5V (LTC1261L-4.5) CC OUT OUT ORDER PART NUMBER TOP VIEW LTC1261LCS8 8 SHDN LTC1261LCS8-4 7 REG LTC1261LCS8-4.5 OUT 6 5 ADJ (COMP) S8 PART MARKING S8 PACKAGE 1261L ...
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... Note 4: The LTC1261L is guaranteed to meet specified performance from and is designed, characterized and expected to meet these extended commercial temperature limits, but is not tested at – and 85 C. Guaranteed I grade parts are available, consult factory. Note 5: The LTC1261L-4 and LTC1261L-4.5 will operate with less than the minimum V – 10.8V not guaranteed to meet the 3 ...
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... LTC1261L W U TYPICAL PERFORMANCE CHARACTERISTICS Output Voltage vs Supply Voltage – 3. – 4V OUT – 3.90 – 3. – – 4. – 4.05 – 4.10 – 4.15 4.5 4.6 4.7 4.8 4.9 5.0 5.1 5.2 SUPPLY VOLTAGE (V) 1261L G04 Supply Current vs Supply Voltage 3 – 2V OUT OUT 2.5 2 – ...
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... SHDN (Pin 8): Shutdown. When this pin is at ground the LTC1261L operates normally. An internal 5 A pull-down keeps SHDN low left floating. When SHDN is pulled high, the LTC1261L enters shutdown mode. In shut- down, the charge pump is disabled, the output collapses to 0V and the quiescent current drops typically. ...
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... The LTC1261L needs only three external capacitors and is available in the MSOP and SO-8 packages THEORY OF OPERATION A block diagram of the LTC1261L is shown in Figure 1. The heart of the LTC1261L is the charge pump core shown in the dashed box. It generates a negative output voltage by first charging the flying capacitor (C1) between V ground ...
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... REG output will stay low. OUTPUT RIPPLE Output ripple in the LTC1261L is present 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 clock frequency of 650kHz, the charge on the output capacitor is refreshed once every 1 ...
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... F ceramic capacitor in parallel with it. The charge pump capacitor is somewhat less critical since its peak current is limited by the switches inside the LTC1261L. Most applications should use a 0 the flying capacitor value. Conveniently, ceramic capacitors are the most common type of 0 ...
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... CLK C 2 FLY Most of this resistance is already provided by the internal switches in the LTC1261L. More than ESR on the flying capacitors will start to affect the regulation at maximum load. RESISTOR SELECTION Resistor selection is easy with the fixed output voltage versions of the LTC1261L— no resistors are needed! Selecting the right resistors for the adjustable parts is only a little more difficult ...
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... C2 OUT GND COMP + 100pF 5V Input, – 0.5V Output GaAs FET Bias Generator 43.2k 10k SHDN REG LTC1261L 3 6 – C2 OUT 12. GND ADJ 1% 100pF – 4V BIAS GaAs TRANSMITTER 1261 TA03 P-CHANNEL – 4V BIAS GaAs 10 F TRANSMITTER + 1261 TA04 ...
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... DWG # 05-08-1610) (4.801 – 5.004) 8 0.228 – 0.244 (5.791 – 6.197 0.053 – 0.069 (1.346 – 1.752) 0 – 8 TYP 0.014 – 0.019 (0.355 – 0.483) LTC1261L 0.118 0.004** (3.00 0.102 0.034 0.004 (0.86 0.102) 0.006 0.004 (0.15 0.102) ...
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... S 3 – 487k) S 1261L TA06 Minimum Parts Count – 4.5V Generator SHDN REG LTC1261L-4 – OUT C1 OUT AT 5mA 4 5 3.3 F GND COMP + COMMENTS 0.4V Dropout Voltage at 150mA, Low Noise, Switched Capacitor Regulated Voltage Inverter Fixed 1. Output from 2. Input, ...