Datasheet
SYNC
GND PGND
SW
R1
560 kW
R2
300 kW
V
O
= 3.3 V
6.8 Hm
C = 22 F
6.3 V
O
m
VIN
LBI
C = 10 F
25 V
I
m
1 Fm
2
3
4
8
9
7
5
11
12
16
10
6
13
14 15
1
V = 4.3 V to 17 V
I
VIN
EN
VINA
PGNDGND PwPD
R5
R6
AGND
TPS62110
SW
LBO
PG
R3
R7
R4
FB
C
ff
10 pF
TPS62110-HT
www.ti.com
SLVSAO9B –DECEMBER 2010– REVISED FEBRUARY 2011
DETAILED DESCRIPTION (continued)
Figure 11. LBI With Increased Hysteresis
NO LOAD OPERATION
When the converter operates in the forced PWM mode and there is no load connected to the output, the
converter regulates the output voltage by allowing the inductor current to reverse for a short time.
THEORY OR OPERATION / DESIGN PROCEDURE
Table 1. List of Inductors
(1)(2)
MANUFACTURER
(3)
TYPE INDUCTANCE DC RESISTANCE SATURATION CURRENT
Coilcraft MSS6132-682 6.8 µH 65 mR (max) 1.5 A
Epcos B82462G4682M 6.8 µH 50 mR (max) 1.5 A
Sumida CDRH5D28-6R2 6.2 µH 33 mR (typ) 1.8 A
SLF6028T-6R8M1R5 6.8 µH 35 mR (typ) 1.5 A
TDK
SLF7032T-6R8M1R6 6.8 µH 41 mR (typ) 1.6 A
7447789006 6.8 µH 44 mR (typ) 2.75 A
Wurth 7447779006 6.8 µH 33 mR (typ) 3.3 A
744053006 6.2 µH 45 mR (typ) 1.8 A
(1) Component selections are for 25°C only and will change for new temperature range.
(2) Components have not been validated for extreme high temperature operation.
(3) The manufacturer's part numbers are used for test purposes only.
Inductor Selection
The control loop of the TPS62110 family requires a certain value for the output inductor and the output capacitor
for stable operation. As long as the nominal value of L × C ≥ 6.2 µH × 22 µF, the control loop has enough phase
margin and the device is stable. Reducing the inductor value without increasing the output capacitor (or vice
versa) may cause stability problems. There are applications where it may be useful to increase the value of the
output capacitor, e.g., for a low transient output voltage change. From a stability point of view, the inductor value
could be decreased to keep the L × C product constant. However, there are drawbacks if the inductor value is
decreased. A low inductor value causes a high inductor ripple current and therefore reduces the maximum dc
output current. Table 2 gives the advantages and disadvantages when designing the inductor and output
capacitor.
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