Datasheet

LTM4637
14
4637fc
For more information www.linear.com/LTM4637
applicaTions inForMaTion
Figure 5. Output Voltage Coincident Tracking Characteristics
4637A F05
TIME
SLAVE OUTPUT
MASTER OUTPUT
OUTPUT
VOLTAGE
Figure 4. Dual Outputs (1.5V and 1.2V) with Tracking
COMP
TRACK/SS
RUN
f
SET
MODE_PLLIN
TEMP
PGOOD
V
OUT
V
OUT_LCL
DIFF_OUT
V
OSNS
+
V
OSNS
–
V
FB
LTM4637
V
IN
R2
10k
R
FB1
40.2k
R4
75k
330pF
2.2µF
C
SS
SOFT-START
CAPACITOR
V
OUT2
1.5V
20A
C8
470µF
6.3V
×2
C11
100µF
6.3V
×2
C
IN1
22µF
16V
×4
INTV
CC
EXTV
CC
V
IN
4.5V TO 16V
SGND GND
+
COMP
TRACK/SS
RUN
f
SET
MODE_PLLIN
TEMP
PGOOD
V
OUT
V
OUT_LCL
DIFF_OUT
V
OSNS
+
V
OSNS
–
V
FB
LTM4637
V
IN
R1
10k
R
FB
60.4k
R3
50k
330pF
V
OUT1
1.2V
20A
C4
470µF
6.3V
×2
C6
100µF
6.3V
×2
INTV
CC
EXTV
CC
4637 F04
SGND GND
+
R
TB
60.4k
R
TA
60.4k
MASTER RAMP
OR OUTPUT
V
IN
4.5V TO 16V
C
IN2
22µF
16V
×4
2.2µF
Temperature Monitoring
A diode connected PNP transistor is used for the TEMP
monitor function by monitoring its voltage over tempera
-
ture. The temperature dependence of this diode voltage
can be understood in the equation:
V
D
= nV
T
ln
I
D
I
S






where V
T
is the thermal voltage (kT/q), and n, the ideality
factor, is 1 for the diode connected PNP transistor be-
ing used
in the LTM4637. I
S
is expressed by the typical
empirical equation:
I
S
=I
0
exp
–V
G0
V
T





