isl6455a Intersil Corporation, isl6455a Datasheet
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isl6455a
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isl6455a Summary of contents
Page 1
... December 21, 2005 Features • Fully integrated synchronous buck regulator + dual LDO • PWM output voltage adjustable. - 0.8V to 2.5V with ISL6455 (VIN = 3.3V) - 0.8V to 3.3V with ISL6455A (VIN = 5.0V) • High output current 600mA • Dual LDO adjustable options - LDO1, 1.2V to Vin-0.3V (3.3Vmax 300mA - LDO2, 1.2V to Vin-0.3V (3.3Vmax 300mA • Ultra-compact DC/DC converter design • ...
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... Pinout Typical Application Schematic 3.3V R1 10k Re FB_PWM Rf PG_PWM 33nF C2 3.3V R3 PG_LDO 10k NOTE: All capacitors are ceramic. 2 ISL6455, ISL6455A ISL6455, ISL6455A (QFN) TOP VIEW SGND FB_LDO2 2 3 FB_LDO1 CC1 4 GND_LDO 5 VOUT1 C10 1.0µF 10µ 8.2µH C7 0.1µ ...
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... RTN SGND SOFT- COMPENSATION START FB_PWM EA COMPENSATION 750kHz OSCILLATOR EN POWER GOOD PWM V OUT UVLO PWM REFERENCE 0.45V SYNC EN 10k 10k 3.3V 3 ISL6455, ISL6455A BAND GAP REF 1.2V WINDOW COMP. POR EN LOGIC THERMAL WINDOW 150°C COMP. SLOPE EN PWM OVERCURRENT, GM OVERVOLTAGE LOGIC PG_PWM 3.3V 10k Gm ...
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... Tech Brief TB379. 2. For θ , the “case temp” location is the center of the exposed metal pad on the package underside. JC Electrical Specifications Recommended operating conditions unless otherwise noted. V 5.0V for the ISL6455A, Compensation Capacitors = 33nF for LDO1 and LDO2. T values are at T PARAMETER V SUPPLY CC ...
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... Electrical Specifications Recommended operating conditions unless otherwise noted. V 5.0V for the ISL6455A, Compensation Capacitors = 33nF for LDO1 and LDO2. T values are at T PARAMETER Efficiency Soft-Start Time OSCILLATOR Oscillator Frequency Frequency Synchronization Range (f SYNC SYNC High Level Input Voltage SYNC Low Level Input Voltage ...
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... Electrical Specifications Recommended operating conditions unless otherwise noted. V 5.0V for the ISL6455A, Compensation Capacitors = 33nF for LDO1 and LDO2. T values are at T PARAMETER ENABLE (EN and (EN_LDO) EN High Level Input Voltage EN Low Level Input Voltage RESET BLOCK SPECIFICATIONS RESET (reset released) RESET (reset asserted) ...
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... PG_LDO Timing Diagram UVLO V PG VFB_LDO PG_LDO THRESHOLD VOLTAGE PG_LDO OUTPUT OUTPUT UNDEFINED NOTE the minimum input voltage for a valid PG_LDO ISL6455, ISL6455A V UVLO RISING MAX +18% FALLING MIN -17% t OUTPUT UNDEFINED t FN9196.0 December 21, 2005 ...
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... This I/O pin senses the output voltage of the PWM OUT converter for the purpose of detecting the over and undervoltage conditions. 8 ISL6455, ISL6455A PG_PWM - This pin is an active pull-up/pull-down able to source/sink 1mA (min.) at 0.4V from V is HIGH when V FB_LDO1 and FB_LDO2 - These pins are used to set the LDO output with the proper selection of resistors ...
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... LSB (but the counter will not "rollover" or count below 0000). If >33% of the PWM cycles go into overcurrent, the counter rapidly reaches count 1111 9 ISL6455, ISL6455A and the PWM output is shut down and the soft-start counter is reset. After 16 clocks the PWM output is enabled and the SS cycle is started. ...
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... PWM Regulator Component Selection INDUCTOR SELECTION A 8.2µH typical output inductor is used with the ISL6455 and a 12µH typical with the ISL6455A PWM section. Values less than this may cause stability problems because of the internal compensation of the regulator. The important parameters of the inductor that need to be considered are the current rating of the inductor and the DC resistance of = ambient temperature, and θ ...
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... The output resistors should be selected so that the minimum output load is about 200 Layout Considerations As for all switching power supplies, the layout is an important step in the design of ISL6455, ISL6455A based power supply due to the high switching frequency and low noise LDO implementations. ...
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... However, no responsibility is assumed by Intersil or its subsidiaries for its use; nor for any infringements of patents or other rights of third parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of Intersil or its subsidiaries. For information regarding Intersil Corporation and its products, see www.intersil.com 12 ISL6455, ISL6455A L24.4x4B 24 LEAD QUAD FLAT NO-LEAD PLASTIC PACKAGE (COMPLIANT TO JEDEC MO-220VGGD-2 ISSUE C) ...