EC4304B Datasheet, PDF (2/11 Pages) E-CMOS Corporation – PWM Control 1.2A Step-Down Converter

PWM Control 1.2A Step-Down Converter
PIN DESCRIPTION
EC4304B
SYMBO ^SOT-23
L ^LX
1
GND
2
ADJ
3
ISENS
4
E
VIN
5
SOT-89
1
2
3
DESCRIPTION
Drain of NDMOS switch
Ground
Multi-function On/Off and brightness control pin:
• Leave floating for normal operation.(VADJ = VREF = 1.25V giving
nominal average output current IOUTnom = 0.1/RS)
• Drive with DC voltage (0V < VADJ < 2.5V) to adjust output current
from 0% to 200% of IOUTnom
• Drive with PWM signal from open-collector or open-drain transistor, to
adjust output current. Adjustment range 0% to 100% of IOUTnom for
f >10kHz and 0% to 100% of IOUTnom for f < 500Hz
Connect resistor RS from this pin to VIN to define nominal average output
4
current IOUTnom = 0.1/RS
Input voltage (7V to 30V). Decouple to ground with 10uF or higher
5
X7R ceramic capacitor close to device
ABSOLUTE MAXIMUM RATINGS
Parameter
Voltage on intput pin relative to GND
ISENSE pin Voltage
ADJ and EN pin Voltage
Operating Temperature Rang
Maximum Soldering Temperature (at leads, 10 sec)
Storage Temperature Rang
Power Dissipation, PD @ TA = 25°C
Package Thermal Resistance, θJA
Symbol
VIN
TA
TLEAD
TS
SOT-23
SOT-89
SOT-23
SOT-89
Value
-0.3 to +36
-5 to +0.3
-0.3 to +6
-40 to +125
300
-65 to +150
0.35
0.5
250
200
Unit
V
V
V
C
C
C
W
°C/W
E-CMOS Corp. (www.ecmos.com.tw)
Page 2 of 11
2011/10/06