Ricoh RP500x Series Data Manual (Part 1) User Guide

RP500x Series

600m A∗ PWM/VFM Step-down DC/DC Converter with Synchronous Rectifier

The RP500x Series are low supply current CMOS-based PWM/VFM step-down DC/DC converters with synchronous rectifier. RP500x can be selected from two control types - fixed PWM control or PWM/VFM auto switching control in which mode automatically switches to high-efficiency VFM mode in low output current. RP500x includes a soft start circuit, an under-voltage lockout circuit (UVLO), and a latch protection circuit. By simply using an inductor and capacitors as external components, a high-efficiency step-down DC/DC converter can be easily configured.

FEATURES • Supply Current (IDD1)·······················Typ. 400μA (VIN=VCE=5.5V, VOUT=0V) • UVLO Detect Voltage (VUVLO) ·············Typ. 2.2V • Supply Current (IDD2)·······················Typ. 100μA (VIN=VCE=VOUT=5.5V) • Soft Start Time (tstart)························Typ. 0.12ms • Standby Current (Istandby)··················Max. 5μA (VIN=5.5V, CE="L") • Coil-current Limit Circuit ·················Current limit Typ. 900m A • Input Voltage Range (VIN) ···············2.55V to 5.5V • Latch Protection Circuit ··················Delay time for protection Typ. 1.5ms • Output Voltage Range (VOUT)··········1.1V to 3.3V (internally fixed) • Auto-Discharge Function················ 3, 4 Version • Output Voltage Accuracy ················± 1.5% • Packages········································WLCSP-6-P2, DFN1616-6, • Output Current (IOUT)·······················600m A∗ DFN(PLP)1820-6, SOT-23-6W • Oscillator Frequency (fosc)···············1.2MHz • Ceramic capacitors can be used ····CIN=COUT=10μF or more • Oscillator Maximum Duty Cycle (Maxduty) ··Min. 100%

∗)This is an approximate value, because output current depending on conditions and external parts.

BLOCK DIAGRAM TYPICAL APPLICATION

RP500x RP500x

VIN VOUT

VIN LX

Chip Ramp Current

CE 4.7μH

Enable Compensation Feedback

∗1 CIN COUT

OSC Current CE VOUT

Protection LX

ffi ci en cy

Vref PWM Switching PGNDAGND

Control Control

Soft Start VOUT

L : VLF3010AT-4R7MR30 CIN, COUT : C2012JB0J106 (TDK)

∗1) This block does not exist in xx2A/xx4A ∗2) This block does not exist in xx1A/xx2A

SELECTION GUIDES

.xx. : Specify the output voltage within the range of

Halogen Free Package Q'ty per Reel Part No.

1.1V (.11.) to 3.3V (.33.) in 0.1V steps.

WLCSP-6-P2 5,000 pcs RP500Z .xx∗ A-E2-F

.∗ . : Select from (.1.) PWM/VFM auto switching, without auto-discharge function,

DFN1616-6 5,000 pcs RP500L .xx∗ A-TR

(.2.) Fixed PWM, without auto-discharge function,

DFN(PLP)1820-6 5,000 pcs RP500K .xx∗ A-TR (.3.) PWM/VFM auto switching, with auto-discharge function or

SOT-23-6W 3,000 pcs RP500N .xx∗ A-TR-FE (.4.) Fixed PWM, with auto-discharge function. (RP500Kxx3A does not exist.)

PACKAGES (Top View) TYPICAL CHARACTERISTIC

WLCSP-6-P2 DFN1616-6 DFN(PLP)1820-6 SOT-23-6W RP500x331A/333A Efficiency vs. Output Current

1 VOUT 1 CE 1 CE 1 VOUT 2 PGND 2 AGND 2 AGND 2 PGND VIN=4.3V

3 LX 3 VIN 3 VIN 3 LX VIN=5V

4 VIN 4 LX 4 LX 4 VIN 5 AGND 5 PGND 5 PGND 5 AGND 6 CE 6 VOUT 6 VOUT 6 CE

Output Current IOUT (m A)

∗) The tab is substrate level (GND).

APPLICATIONS • Power source for battery-powered equipment • Power source for hand-held communication equipment, cameras, and VCRs • Power source for compact HDD No.EK-155-111001 Step-down DC/DC Converter