Datasheet
SYNC
GND PGND
SW
R1
560k
R2
300k
V
O
=3.3V
6.8 Hm
C =22 F
6.3V
O
m
VIN
LBI
C =10 F
25V
I
m
1 Fm
2
3
4
8
9
7
5
11 12
16
10
6
13
14
15
1
V =4.3Vto17V
I
VIN
EN
VINA
PGNDGND PwPD
R5
R6
AGND
TPS62110
SW
LBO
PG
R3
R7
R4
FB
C
ff
10pF
TPS62110-Q1
www.ti.com
SLVSA54A –FEBRUARY 2010–REVISED SEPTEMBER 2012
Figure 9. 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 OF OPERATION AND DESIGN PROCEDURE
Table 1. List of Inductors
MANUFACTURER
(1)
TYPE INDUCTANCE DC RESISTANCE SATURATION CURRENT
Coilcraft MSS6132-682 6.8 µH 65 mΩ (max) 1.5 A
Epcos B82462G4682M 6.8 µH 50 mΩ (max) 1.5 A
Sumida CDRH5D28-6R2 6.2 µH 33 mΩ (typ) 1.8 A
SLF6028T-6R8M1R5 6.8 µH 35 mΩ (typ) 1.5 A
TDK
SLF7032T-6R8M1R6 6.8 µH 41 mΩ (typ) 1.6 A
7447789006 6.8 µH 44 mΩ (typ) 2.75 A
Wurth 7447779006 6.8 µH 33 mΩ (typ) 3.3 A
744053006 6.2 µH 45 mΩ (typ) 1.8 A
(1) The manufacturer's part numbers are used for test purposes only.
Inductor Selection
The control loop of the TPS62110 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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