SMM605
Preliminary Information
APPLICATIONS INFORMATION (CONTINUED)
+12VIN(+6V to 14V)
C3
0.1uF
VTRIMlow=0.3V, VOSENSE=0.8V
The current through R3 is
ITRIM=(0.8-0.3)/RTRIM
(ITRIM)(R4) > 15% of VOUT
RTRIMmax should be no greater
then the calculated value
C4
0.1uF
C5
0.01uF
R5 10K
46
48
47
14
R4 10K
U1
START
READY
4
7
START
READY
For Example, If Vout=3.3V, R4=63.4K
15% of Vout=0.5V
C1 should be as close ITRIM=8uA
to the SMM105 as
RTRIM=62.5K so Rtrim should be
possible
next value down from 62.5K
C1 1uF
TRIM_CAPX
TRIMX
VMX
R3 RTRIM
LT3707 Switching Regulator
+Vin
+Vout
VDD
VDD_CAP
12VIN
VREF_CNTL
VOUT
R4
RSET1
R2 10K
R1 10K
2
1
3
SCL
SDA
A2
SMM605
FILT_CAP
15
GND
GND
GND
GND
Gnd
D1
DIODE
C6
0.01uF
1
3
5
7
9
J1
2
4
6
8
10
PGOOD
C2
0.02uF
U2
START
VOSENSE
R5
20k
The SMM605 START pin must be inactive during power-up so
SMX3200 I2C Programming that the TRIM pin is high impedence. Once power is nominal,
the START pin can be active to start margin and ADOC
Connector 10 pin Header
functions
R1 and R2 need only be
placed once on the I2C bus
Figure 8 – SMM605 Applications schematic for an adjustable switching regulator (Full regulator circuit not
shown).
Gnd
SCL
Gnd3
SDA
Rsrv5
MR
+10V Rsrv8
+5V Rsrv10
Summit Microelectronics, Inc
5
6
12
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2064 1.1 09/16/03
12
SUMMIT [ SUMMIT MICROELECTRONICS, INC. ]
