MAX1605 Maxim, MAX1605 Datasheet - Page 9

• Manufacturer Part Number: MAX1605
• Description: 30V Internal Switch LCD Bias Supply
• Manufacturer: Maxim

Figure 4. Negative Voltage for LCD Bias
saturation region. When shut down, the input voltage
exceeds the emitter voltage so the inactive transistor
provides high-impedance isolation between the input
and output. Efficiency will be slightly degraded due to
the PNP transistor saturation voltage and base current.
Figure 5. Output Disconnected in Shutdown
V
CC
ON
= 2.4V TO 5.5V
V
IN
= 0.8V TO V
OFF
OUT
V
SHDN
LIM
CC
MAX1605
10µH
L1
_______________________________________________________________________________________
GND
LX
FB
0.8V TO
V
2.4V TO
5.5V
V
V
OUT
IN
CC
30V Internal Switch LCD Bias Supply
=
=
ON
R1
R2
0.1µF
V
(V
R3 = 180k
C6
SET
OUT
= 18.3V
+ 0.3V)
OFF
Ω
1µF
C5
2N2907A
V
SHDN
LIM
CC
MAX1605
10µH
V
L1
OUT
= 18V
GND
LX
FB
240kΩ
D3**
1Ω
R3
R1
TRANSISTOR COUNT: 2329
*D1, D2 = CENTRAL SEMICONDUCTOR
0.1µF
**D3 = CENTRAL SEMICONDUCTOR
C3
C1
1000pF
16.5kΩ
R2
CMPD7000 DUAL
CMSD4448 (1N4148)
D2*
D1*
C4
0.01µF
1µF
C2
-19V
V
NEG
Chip Information
9