Datasheet

MAX845
Isolated Transformer Driver
for PCMCIA Applications
4 _______________________________________________________________________________________
____________________________Typical Operating Characteristics (continued)
( Typical Operating Circuit , V
IN
= 5V, C1 = 0.1µF, C2 = C3 = 0.33µF, T1 = Halo TGM-010P3, CR1 = CR2 = MBR0520, FS = V
CC
,
T
A
= +25°C, unless otherwise noted.)
SWITCHING WAVEFORMS
(TWO CYCLES)
5V/div
400ns/div
D1
D2
SWITCHING WAVEFORM
(BREAK-BEFORE-MAKE)
500mV/div
200ns/div
D2OFFD1OFF
CIRCUIT
OF FIG. 1
D2ON D1ON
TIME FROM SHUTDOWN TO POWER-UP
2V/div
5µs/div
SD
OUTPUT
_____________________Pin Description
No Connect. Not internally connected.N.C.5
+5V Supply VoltageV
CC
6
Ground. Connect both GND1 and GND2 to
ground.
GND27
Open Drain of N-Channel Transformer Drive 2D28
Shutdown. Ground for normal operation,
connect to V
CC
for shutdown.
SD4
Frequency Select (internal pull-up). If FS =
V
CC
or open, switch frequency = 725kHz; if
FS = 0V, switch frequency = 535kHz.
FS3
PIN
Ground. Connect both GND1 and GND2 to
ground.
GND12
Open Drain of N-Channel Transformer Drive 1D11
FUNCTIONNAME
MAX845
D1
D2FS
GND1 GND2
V
CC
1
8
4
6
2 7
3
SD
FREQUENCY
SELECT
ON / OFF
R2
50Ω
R1
50Ω
V
IN
5V
C1
0.1µF
Figure 1. Test Circuit