ELM92xxxx
CMOS 600kHz High output current PWM step-up DC/DC converter
■General description
ELM92xxxx is CMOS PWM step-up DC/DC converter which consists of reference voltage source, error
amplifier, oscillation circuit, start-up circuit, output voltage setting resistor, LX transistor and switching current
limiter. For external parts, coil, diode and capacitor are possible choices; with external parts, ELM92 series is
able to acquire constant output voltage higher than input voltage. The standard output voltages are 2.7V, 3.0V,
3.3V, and 5.0V; ELM92 series can also be designed as semi-custom IC within the range of 2.5V to 5.5V by 0.1V
step. Meanwhile, 600kHz high frequency PWM control scheme makes it easy to design DC/DC converter which
can generate large output current with high stability and small ripples by only using small external inductor.
With newly developed intermittent operation control scheme, ELM92 series is able to work with high efficiency
under wide range of load conditions.
■Features
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Output voltage range
Low voltage operation
Oscillating frequency
Output current(e.g.)
CE(Chip-enable pin) available
High efficiency
Switching current limiter
Package
: 2.5V to 5.5V (by 0.1V)
: Vin≥0.9V
: Typ.600kHz
: 250mA (When Vin=1.5V, Vout=3.0V)
: Max. 0.5μA (ELM92xx2x Iss at Shutdown)
: Typ. 85%
: SOT-89, SOT-89-5, SON-6
■Application
• Constant voltage source for battery-operated devices
• Constant voltage source for PDAs, cameras, portable communications equipments and videos
• Local regulator
■Maximum absolute ratings
Parameter
Apply voltage to LX pin
Apply voltage to VOUT pin
Apply voltage to CE pin
Power dissipation
Operating temperature
Storage temperature
Symbol
Vlx
Vout
Vce
Pd
Top
Tstg
Limit
Vss-0.3 to 8.0
Vss-0.3 to 8.0
Vss-0.3 to 8.0
300 (SOT-89)
500 (SOT-89-5)
500 (SON-6)
-40 to +85
-55 to +125
Unit
V
V
V
mW
°C
°C
15 - 1