Is o la t e d Tra n s fo rm e r Drive r
fo r P CMCIA Ap p lic a t io n s
____________________________Typ ic a l Op e ra t in g Ch a ra c t e ris t ic s (c o n t in u e d )
(Typical Operating Circuit, V = 5V, C1 = 0.1µF, C2 = C3 = 0.33µF, T1 = Halo TGM-010P3, CR1 = CR2 = MBR0520, FS = V
,
IN
CC
T
A
= +25°C, unless otherwise noted.)
SWITCHING WAVEFORM
(BREAK-BEFORE-MAKE)
SWITCHING WAVEFORMS
(TWO CYCLES)
D1OFF
D2OFF
MAX845
D1
D2
500mV/div
5V/div
CIRCUIT
OF FIG. 1
D2ON
D1ON
200ns/div
400ns/div
TIME FROM SHUTDOWN TO POWER-UP
SD
2V/div
OUTPUT
5µs/div
_____________________P in De s c rip t io n
V
IN
PIN
NAME
FUNCTION
5V
C1
0.1µF
R1
50Ω
6
1
D1
Open Drain of N-Channel Transformer Drive 1
V
CC
Ground. Connect both GND1 and GND2 to
ground.
2
3
4
GND1
FS
1
4
SD
D1
D2
ON / OFF
Frequency Select (internal pull-up). If FS =
R2
50Ω
V
CC
or open, switch frequency = 725kHz; if
MAX845
FS = 0V, switch frequency = 535kHz.
3
8
Shutdown. Ground for normal operation,
connect to V for shutdown.
CC
FS
SD
FREQUENCY
SELECT
GND1
GND2
5
6
N.C.
No Connect. Not internally connected.
+5V Supply Voltage
2
7
V
CC
Ground. Connect both GND1 and GND2 to
ground.
7
8
GND2
D2
Open Drain of N-Channel Transformer Drive 2
Figure 1. Test Circuit
4
_______________________________________________________________________________________
MAXIM [ MAXIM INTEGRATED PRODUCTS ]
