ELM91xxxxA CMOS PFM Step-up DC/DC converter and controller
■Pin configuration
SOT-89(TOP VIEW)
SOT-23(TOP VIEW)
SC-70(TOP VIEW)
3
3
1
2
1
2
1
2
3
ELM91xx1AA, ELM91xx3AA
ELM91xx1BA, ELM91xx3BA ELM91xx1CA, ELM91xx3CA
Pin No.
Pin name
Pin No.
Pin name
Pin No.
Pin name
1
VSS
1
VSS
1
2
VSS
VOUT
ELM91xx1AA: LX
ELM91xx3AA: EXT
ELM91xx1CA: LX
ELM91xx3CA: EXT
VOUT
ELM91xx1BA: LX
ELM91xx3BA: EXT
VOUT
2
3
2
3
3
■Standard circuit
33 H
�
MA2Z748
MA735
Vin
100 H
�
+
EXT
VOUT
LX
VOUT
Vout
Vin
Vout
ELM91xx3xA
ELM91xx1xA
Cin
100 F
�
+
+
+
Cin
47 F
�
Cout
47 F
Cout
100 F
�
VSS
VSS
�
■Block diagram
ELM91xx1xA
ELM91xx3xA
Vlx
Limiter
VOUT
LX
VOUT
P.F.M.
OSC
P.F.M.
OSC
EXT
+ -
+ -
Start-up
Start-up
Vref
Vref
VSS
VSS
22 - 2
ELM-TECH [ ELM Technology Corporation ]
