ELM620BA Datasheet, PDF (3/10 Pages) ELM Technology Corporation – 1.4MHz high efficiency synchronous PWM step up DC/DC converter

ELM620BA 1.4MHz
high efficiency synchronous PWM step up DC/DC converter
■Standard circuit
L=2.2µH
Vin
+
Cin=
22µF
SW
VIN VOUT
ELM620BA
ON/OFF
EN
FB
GND
Optional
schottky
R1=
1.02MΩ
1%
R2
604kΩ
1%
Vout
Cout
22µF
Vout=(1+ ^R1 )×1.203
R2
■Block diagram
1V to 5V
Input
Vin
Start-up
OSC
Cin
L
22µF ^2.2µH
Optional
schottky
Vout ⁺
good _{� 2.3V}
A
A/B MUX
B
SW
0.45Ω
Vout
Ramp Gen
1.4MHz
EN _Shutdown
control
ELM620BA
PWM
control
Slope
comp
PWM
comp
+
�
�
Shutdown
Sync drive
control
�
0.35Ω
Current
sense
Cff
optional
Rc
80k
Cp2
Cc
2.5pF
150pF
GND
gm _� ^FB
error
AMP +
1.203V
ref
Vout
R1
1.02M
1%
Cout
22µF
R2
604k
1%
10 - 3
Rev.1.0