RICOH R1212D Series PWM Step-up DC-DC Controller Data Sheet User Manual

R1212D Series PWM Step-up DC/DC Controller

The R1212D Series are low supply current CMOS-based PWM step-up DC/DC controllers. R1212D 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 capacitor (The oscillator maximum duty cycle can be selected from the type with/without internal limit.) The oscillator frequency can be selected from 300k Hz, 700k Hz, or 1.4MHz. 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. R1212D also includes an under-voltage lockout circuit (UVLO).

FEATURES • Supply Current (IDD1)·······················Typ. 400μA (300k Hz), Typ. 600μA (700k Hz), • Temp. coeff. of Feedback Voltage····· ± 150ppm/°C

Typ. 900μA (1.4MHz) (VIN=5.5V, VDLY=VFB=0V, • Oscillator Frequency (fosc)∗ ············· Select from 700k Hz, 1.4MHz or 300k Hz.

EXT at no load) • Oscillator Maximum Duty Cycle (Maxduty)∗ ···· Set with external resistors • Input Voltage Range (VIN) ··············2.2V to 5.5V • UVLO Detect Voltage (VUVLO)∗ ············· Select from 1.9V, 2.1V or 2.8V. • Output Voltage Range ····················Externally adjustable (Feedback voltage : 1.0V) • Soft Start Time (tstart) ·························· Set with an external resistor and • Feedback Voltage Accuracy ···········± 1.5% capacitor

• Package ········································· SON-8

∗) For information about combination of oscillator frequency, oscillator maximum duty cycle, and UVLO detect voltage, see SELECTION GUIDE.

BLOCK DIAGRAM TYPICAL APPLICATION

Internal VR VIN R3

VREFOUT VREFOUT UVLO VIN EXT NMOS

ff ic ie C4

OSC DELAY VFB C3

EXT GND AMPOUT

PWM Comp

Latch VREFOUT DTC

VREF R5 R6 C7

Error Amp.

AMPOUT NMOS : CPH6415, L : VLP5612T, 10μH (A), 4.7μH (B), 22μH (C), SD : CRS02,

C1 : 2.2μF, C2 : 1μF, C3 : 15μF, C4=C5 : 1000p F (A), 680p F (B), 1500p F (C), C6 : 0.1μF, C7 : 0.1μF, R3 : 1kΩ, R4 : 4.7kΩ, R5 : 240kΩ, R6 : 300kΩ Output voltage set value 5V⋅⋅⋅R1 : 120kΩ, R2 : 30kΩ, 10V⋅⋅⋅R1 : 180kΩ, R2 : 20kΩ, DELAY 15V⋅⋅⋅R1 : 140kΩ, R2 : 10kΩ

SELECTION GUIDE

.0A. : 700k Hz, No internal limit, 1.9V

Halogen Free Package Q'ty per Reel Part No.

.0B. : 1.4MHz, No internal limit, 1.9V

- SON-8 3,000 pcs R1212D10.∗$ -TR-F LO AD

.1A. : 700k Hz, Internal limiting Typ. 90%, 2.1V .1C. : 300k Hz, Internal limiting Typ. 91.5%, 2.1V ∗$ : Specify a combination of the oscillator frequency, oscillator .2A. : 700k Hz, Internal limiting Typ. 90%, 2.8V maximum duty cycle internal limit, and UVLO detect voltage. .2C. : 300k Hz, Internal limiting Typ. 91.5%, 2.8V

PACKAGE TYPICAL CHARACTERISTIC

SON-8 R1212D100A Efficiency vs. Output Current

Bottom View Top View

VOUT=5V

1 EXT VFB 2 GND VREFOUT 3 DTC AMPOUT

4 DELAY VIN

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-109-111001 Step-up DC/DC Converter