CAT3606 datasheet(4/11 Pages) CATALYST

4 / 11 page

CAT3606

Doc. No. 5009, Rev. B

Characteristics subject to change without notice

BLOCK DIAGRAM

BASIC OPERATION

At power-up, the CAT3606 starts operation in 1x

mode. If it is able to drive the programmed LED

current, it continues in 1x mode. If the battery

voltage drops to a level where the LED current

cannot be met, the driver automatically switches

into 1.5x mode, to boost the output voltage high

enough to achieve the nominal LED current.

The above sequence is reinitialized each and every

time the chip is powered up or is taken out of

shutdown mode (via EN pin). The use of the Main

and Sub display enable pins (

ENM or ENS) does

not affect the mode of operation.

Figure 1: CAT3606 Functional Block Diagram

LED CURRENT SETTING

The LED current is set by the external resistor RSET

connected between the RSET pin and ground.

Table 1 lists various LED currents and the associ-

ated RSET resistor value for standard 1% precision

surface mount resistors.

)

(

Ω

Ω)

Table 1. RSET Resistor Selection

1.2V

Reference

1MHz

Oscillator

Mode Control

1x mode (LDO)

1.5x Charge Pump

VIN

CIN

≤VIN≤4.2V

Battery

RSET

ENM

ENS

LED1

LED2

LED3

LED4

LED5

LED6

LED Output

Selection

6 Current

Sink Regulators

COUT

20mA

VOUT

C1-

C2-

C1+

C2+

Sub

Main

GND

Current

Setting

CAT3606 Datasheet(PDF) 4 Page - Catalyst Semiconductor

CAT3606 Datasheet(HTML) 4 Page - Catalyst Semiconductor

Html Pages

1 2 3 4 5 6 7 8 9 10 11

Datasheet Download

Link URL