Datasheet

V
I
1.8Vto3.8V
TPS62510
PGND
L1
2.2 Hm
C2
22 Fm
C3
22pF
R1
300kW
R2
200kW
R4
200kW
V1
OutputofExternal
DC-DCConverter
e.g.I/ORail
R3
300kW
Cf
100nF
Rf1 W
V2
1.5Vto1.5 A
C1
10 Fm
SW
FB
PG
AGND
PVIN
7
AVIN
EN
OVT
MODE
10
5
6
8
9
2
1
4
3
V2
Time
V1
Voltage
R1
R2
<
R3
R4
1.5V-0.6V
0.6V
=1.5
R3
R4
V2-V
ref
V
ref
= =
(3)
200k
300k+200k
V2
V
ref
V2 =V x
(tracking) (OVT)
R4
R3+R4
=V1x
1.5V
0.6V
=V1x x
V2
V
ref
=V1
(4)
V2
Time
V1
R1
R2
=
R3
R4
Voltage
TPS62510
SLVS651A – MAY 2006 – REVISED JULY 2009 ................................................................................................................................................................ www.ti.com
Figure 18. Output Voltage Tracking, V2 Tracks V1
In this application, the output voltage (V2) of the TPS6251x tracks the voltage (V1) as long as the OVT voltage is
smaller then the internal device reference voltage, V
ref
= 0.6 V. Depending on the resistor divider (R3, R4), the
tracking can be adjusted. V2 can rise faster, at the same timer, or slower than V1.
Figure 19. V2 Comes Up Before V1
Simultaneous tracking is achieved when the resistor divider (R3/R4) is equal to the resistor divider of the
TPS65210.
Equation 3 and Equation 4 are used with the fixed and adjustable version of the TPS6251x. If V2 needs to rise
before V1, then R4 must be increased as shown in Figure 20 .
Figure 20. Simultaneous Tracking of V2 and V1
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