Ricoh R1215D Series PWM Step-up DC DC Controller Manual

R1215D Series PWM Step-up DC/DC Controller

The R1215D Series are low supply current CMOS PWM step-up DC/DC controllers. R1215D does not include an internal output transistor. By simply using a power MOS, an inductor, a diode, resistors, and capacitors as external components, a high-efficiency step-up DC/DC converter can be easily configured. The oscillator maximum duty cycle and soft start time as well as phase compensation can be set with external resistors and capacitors (The oscillator maximum duty cycle does not include internal limit.) The oscillator frequency can be selected from 700k Hz or 1.4MHz. The input voltage of R1215D is lower than the R1212D. The voltage range is 1.8V (2.0V) to 5.5V. The latch type protection circuit embedded into the device latches the external driver in the "OFF" state when the oscillator maximum duty cycle continues for a predetermined period of time setting by an external capacitor. R1215D also includes an under-voltage lockout circuit (UVLO).

FEATURES • Supply Current (IDD1)·······················Typ. 600μA (700k Hz), Typ. 900μA (1.4MHz) • Oscillator Frequency (fosc)··················700k Hz, 1.4MHz

(VIN=5.5V, VDLY=VFB=0V, EXT at no load) • Oscillator Maximum Duty Cycle (Maxduty) ·····Set with external resistors

• Input Voltage Range (VIN) ··············2.0V to 5.5V (A/B Version) • UVLO Detect Voltage (VUVLO) ············1.79V, 1.60V

1.8V to 5.5V (E/F Version) • Soft Start Time (tstart) ··························Set with an external

• Output Voltage Range ····················Externally adjustable (Feedback voltage : 1.0V) resistor and capacitor • Feedback Voltage Accuracy ···········± 1.5% • Package·············································SON-8 • Temp. coeff. of Feedback Voltage·····± 150ppm/°C

BLOCK DIAGRAM TYPICAL APPLICATION

Internal VR VIN R3

ffi ci en cy

VREFOUT VREFOUT UVLO VIN EXT NMOS

OSC DELAY VFB C3

EXT GND AMPOUT

PWM Comp

Latch VREFOUT DTC

Error Amp.

AMPOUT NMOS : CPH6415, L : VLP5612T (10μH), SD : CRS02, C1 : 1μF,

C2 : 1μF, C3 : 15μF, C4 : 1000p F, C5 : 2200p F, C6 : 0.1μF, C7 : 0.1μF, R3 : 1kΩ, R4 : 4.7kΩ, R5 : 68kΩ, R6 : 240kΩ Output voltage set value 9V⋅⋅⋅R1 : 160kΩ, R2 : 20kΩ

DELAY

SELECTION GUIDE

.$. : Specify a combination of the oscillator frequency and UVLO

Halogen Free Package Q'ty per Reel Part No.

detect voltage.

LO AD

- SON-8 3,000 pcs R1215D002.$ -TR-F .A. : 700k Hz, 1.79V, .B. : 1.4MHz, 1.79V, .E. : 700k Hz, 1.60V, .F. : 1.4MHz, 1.60V

PACKAGE TYPICAL CHARACTERISTIC

SON-8 R1215D002E Efficiency vs. Output Current

Bottom View Top View

VOUT=9V, Frequency=700k Hz

1 EXT VFB 2 GND VREFOUT

3 DTC AMPOUT

4 DELAY VIN 5.5V

Output Current IOUT(m A)

∗) The tab suspension leads are substrate level (GND).

APPLICATIONS • Power source for hand-held equipment • Power source for LCD and CCD

No.EK-134-111001 Step-up DC/DC Converter