Datasheet LTC3422 (Analog Devices) - 7

HerstellerAnalog Devices
Beschreibung1.5A, 3MHz Synchronous Step-Up DC/DC Converter with Output Disconnect
Seiten / Seite16 / 7 — BLOCK DIAGRA. OPERATIO. LOW VOLTAGE START-UP
Dateiformat / GrößePDF / 271 Kb
DokumentenspracheEnglisch

BLOCK DIAGRA. OPERATIO. LOW VOLTAGE START-UP

BLOCK DIAGRA OPERATIO LOW VOLTAGE START-UP

Modelllinie für dieses Datenblatt

Textversion des Dokuments

LTC3422
W BLOCK DIAGRA
L1 OPTIONAL 4.7µH VIN 1V TO 4.5V + CIN 10µF 5 2 1 SHDN VIN SW BULK VIN CONTROL SIGNALS SHUTDOWN ANTIRING CURRENT SENSE AND SHDN VOUT VBIAS V 10 OUT 2.25V TO 5.25 PWM LOGIC AND – + DRIVERS IZERO CURRENT COMP SENSE BURST SLEEP BURST COMP – 1.216V REFERENCE 0.88V + 0.88V BURST THERMAL MODE SHUTDOWN PWM CONTROL AWAKEN COMP – + – COMP – g + m ERROR R1 –2% AMPLIFIER – FB C 6 OUT 22µF R2 + 1.216V + VC + Σ IMAX 7 COMP 1.5A + CC1 – 1nF START-UP RZ CC2 CURRENT SLOPE START-UP 15k 22pF RAMP COMPENSATION SOFT-START AND THERMAL REG OSCILLATOR EXPOSED PAD RT SYNC BURST SS 11 8 9 3 4 3422 BD RT 28k RB CB CSS 301k 2.2nF 0.1µF
U OPERATIO LOW VOLTAGE START-UP
increased in conjunction with the soft-start ramp. Switch- ing frequency is also internally controlled during start-up. The LTC3422 includes an independent start-up oscillator The device can start up under some load (see graph of designed to start up at input voltages of 0.88V typical. Start-Up Voltage versus Output Current). Soft-start and During start-up, the peak current limit is gradually 3422fa 7