LX1661 Microsemi Corporation, LX1661 Datasheet
LX1661
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LX1661 Summary of contents
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... The LX1660 and LX1661 Are Mono- lithic Switching Regulator Controller ICs designed to provide low-cost, high- performance adjustable power supply for microprocessors and other applications requiring a fast transient response and a high degree of accuracy ...
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LX1660/1661 ...
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... 12V, Out Freq = 200kHz 10V 0.1µF typ.) HICCUP LX1660/1661 LX1660 LX1661 Min. Typ. Max. Min. Typ. Max. 1.98 2 2.02 1. 180 210 240 180 210 240 180 ...
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LX1660/1661 V CC ENABLE ADJ SGND REF 40mV ...
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... This pin is the inverting input of the error comparator. INV NINV/SS 6 This pin is the non-inverting input of the error comparator (LX1661 only: 40mV offset between this pin and error comparator). This pin is pulled low during sleep-mode to allow soft-start function during start up hiccup-mode capacitor connected to this pin adjusts duty cycle. ...
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... LX1661. LX1661 Only: The INV pin is connected to the positive side of the sense resistor (between the inductor and the sense resistor) — See Figure 2. The LX1661 has a 40mV offset to the NINV pin to enhance transient response, as shown in Figure 3 below. Steady-state output voltage ...
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... ERROR VOLTAGE COMPARATOR The error voltage comparator compares the feedback voltage at the positive side of the sense resistor to the set voltage (set voltage plus 40mV in LX1661). An external filter is recommended for high- frequency noise. CURRENT LIMIT AND HICCUP SECTIONS Current limiting is performed by sensing the inductor current across the sense resistor ...
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... GND VID0 Note 1. Setup shown is for 5V application. For 12V input change the following: - Close JP1 and JP4 Figure 5 — Full Featured Voltage Regulator Using LX1661 Controller And LX1670 Programmable Reference / DAC Chip For Pentium Pro Processor Or Pentium II Processor Applications ...
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... OUTEN 12V LX1661 1µ TDRV ADJ 3 14 SGND ...
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... SELECTING BETWEEN THE LX1660 AND THE LX1661 In order to provide maximum user versatility, the Advanced PWM Controller is offered in two versions: the LX1660 and the LX1661. The LX1661 has a 40mV offset built-in which compensates for the current sense resistor voltage drop. This allows optimal transient response for high-speed systems, such as Pentium Pro processor power supplies ...
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INPUT CAPACITOR The input capacitor and the input inductor are to filter the pulsating current generated ...
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LX1660/1661 CURRENT LIMIT (continued) Recommended sense resistor sizes are given in the following table: TABLE 3 ...
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HICCUP CAPACITOR SELECTION (continued) The resulting time is the duration allowed for the 10% duty ...
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LX1660/1661 USING THE LX1660/1661 IN PROGRAMMABLE APPLICATIONS The LX1660/61 device may be used in conjunction with ...
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Input De-coupling (V ) Capacitor CC Ensure that this 1µF capacitor is placed as close ...