ltc3834-1 Linear Technology Corporation, ltc3834-1 Datasheet - Page 15

• Manufacturer Part Number: ltc3834-1
• Description: 30?a Iq Synchronous Step-down Controller
• Manufacturer: Linear Technology Corporation

APPLICATIO S I FOR ATIO
Alternatively, the TRACK/SS pin can be used to track two
(or more) supplies during start-up, as shown qualitatively
in Figures 4a and 4b. To do this, a resistor divider should
be connected from the master supply (V
SS pin of the slave supply (V
During start-up V
by the resistor divider:
For coincident tracking (V
R
R
V
A
B
V
OUT
X
= R
= R
=
TRACKA
TRACKB
R
TRACKA
R
A
OUT
U
will track V
(4a) Coincident Tracking
•
R
TRACKA
U
OUT
TIME
OUT
R
= V
X
A
Figure 4. Two Different Modes of Output Voltage Tracking
according to the ratio set
), as shown in Figure 5.
X
+
+
W
during start-up),
R
R
TRACKB
B
Figure 5. Using the TRACK/SS Pin for Tracking
3834-1 F04A
X
) to the TRACK/
V
V
X
OUT
(MASTER)
V
(SLAVE)
U
x
R
R
TRACKB
TRACKA
V
OUT
RB
RA
INTV
The LTC3834-1 features an internal P-channel low drop-
out linear regulator (LDO) that supplies power at the
INTV
gate drivers and much of the LTC3834-1’s internal cir-
cuitry. The V
to 5.25V. It can supply a peak current of 50mA and must
be bypassed to ground with a minimum of 4.7μF ceramic
capacitor. The ceramic capacitor placed directly adjacent
to the INTV
Good bypassing is needed to supply the high transient
currents required by the MOSFET gate drivers and to
prevent interaction between the channels.
V
TRACK/SS
LTC3834-1
FB
CC
CC
38341 F05
Regulator
pin from the V
CC
IN
(4b) Ratiometric Tracking
and PGND IC pins is highly recommended.
LDO regulates the voltage at the INTV
TIME
IN
supply pin. INTV
3834-1 F04B
LTC3834-1
V
V
X
OUT
(MASTER)
(SLAVE)
CC
powers the
15
CC
38341f
pin