ELM91 Datasheet, PDF (1/22 Pages) ELM Electronics – CMOS PFM Step-up DC/DC converter and controller

ELM91xxxxA CMOS PFM Step-up DC/DC converter and controller
http://www.elm-tech.com
■General description
ELM91xx1xA is CMOS PFM control step-up DC-DC converter; ELM91xx3xA is CMOS PFM control step-
up DC-DC controller, which has large output current capacity by using an external FET switch. ELM91 series
consists of reference voltage source, error amplifier, oscillation circuit, start-up circuit, PFM-control circuit,
switching current limit circuit (ELM91xx1xA only), switching transistor (ELM91xx1xA only) and output
voltage setting resistor. For external parts, coil, diode, MOSFET and capacitor are possible choices. The
standard output voltages are 1.8V,3.0V,3.3V,5.0V; ELM91 series can also be designed as semi-custom IC within
the range of 1.8V to 5.5V by 0.1V step.
■Features
■Application
• Output voltage range : 1.8V to 5.5V (by 0.1V)
• Constant voltage source for battery-
• Low voltage operation : 0.9V(ELM91xx1xA: Iout=1mA)
operated devices
• Oscillating frequency : Typ.100kHz
• Portable communication equipments
• Low power operation : Typ.40µW(ELM91301xA: Typ.100kHz)
and video recorders
• High efficiency
: 85%(ELM9130xxA: Vin=1.5V, Iout=10mA)
• Output current(e.g.) : 100mA(Vin=1.5V, Vout=3.0V)
• Package
: SOT-89, SOT-23, SC-70-5(SOT-353)
■Maximum absolute ratings
Parameter
Apply voltage to LX pin
Apply voltage to VOUT pin
Output current of LX pin
Output current of EXT pin
Power dissipation
Operationg temperature
Storage temperature
Symbol
Limit
Unit
Vlx
Vss-0.3 to 7.0
V
Vout
Vss-0.3 to 7.0
V
Ilx
500
mA
Iext
20
mA
500 (SOT-89)
Pd
250 (SOT-23)
mW
150 (SC-70-5)(SOT-353)
Top
-40 to +85
°C
Tstg
-55 to +125
°C
■Selection guide
ELM91xxxxA-x
Symbol
a, b
Output voltage
c
Switching transistor
d
Package
e
Product version
f
Taping direction
e.g. :
18: Vout=1.8V 30: Vout=3.0V
33: Vout=3.3V 50: Vout=5.0V
1: Internal switch
3: External switch
A: SOT-89
B: SOT-23
C: SC-70-5(SOT-353)
A
S , N: Refer to PKG file
ELM91 x x x x A - x
↑↑↑↑↑ ↑
abcd e f
22 - 1
Rev.1.3