Datasheet
OUT
IN
L OUT
V
1
V
ΔI = V
L
-
´
´ ¦
TPS6236x
PGND
PGND
PGND
AGND
SW
SW
SENSE-
SENSE+
VIN
SCL
SDA
VSEL0
VSEL1
EN
AVIN
VDD
C
AVIN
R
LP
C
VIN
C
OUT
TPS62360, TPS62361B
TPS62362, TPS62363
www.ti.com
SLVSAU9C –MAY 2011–REVISED NOVEMBER 2012
Table 7. List of Recommended Capacitors
CAPACITANCE DIMENSIONS
TYPE MANUFACTURER
[µF] L x W x H [mm
3
]
10 GRM188R60J106M 0603: 1.6 x 0.8 x 0.8 Murata
10 CL10A106MQ8NRNC 0603: 1.6 x 0.8 x 0.8 Samsung
22 GRM188R60G226M 0603: 1.6 x 0.8 x 0.8 Murata
22 CL10A106MQ8NRNC 0603: 1.6 x 0.8 x 0.8 Samsung
DECOUPLING CAPACITORS AT AVIN, VDD
Noise impacts can be reduced by buffering AVIN and VDD with a decoupling capacitor. It is recommended to
buffer AVIN and VDD with a X5R or X7R ceramic capacitor of at least 0.1µF connected between AVIN, AGND
and VDD, AGND respectively. The capacitor closest to the pin should be kept small (< 0.22µF) in order to keep a
low impedance at high frequencies. In general, there is no upper limit for the total capacitance.
Adding a low pass input filter at AVIN (e.g. by adding R
LP
= 10Ω resistor in series) is not mandatory for the
TPS6236x. It can be used if the supply rail at very noisy (e.g. by the use of a pre-regulator) to filter away
aggressive noise. See Figure 49.
Figure 49. Optional Low Pass Filter at AVIN
INDUCTOR SELECTION
The choice of the inductor type and value has an impact on the inductor ripple current, the transition point of
PFM to PWM operation, the output voltage ripple and accuracy. The subsections below support for choosing the
proper inductor.
Inductance Value
The TPS6236x is designed for best operation with a nominal inductance value of 1µH.
Inductances down to 0.47µH nominal may be used to improve the load transient behavior or to decrease the total
solution size. See OUTPUT FILTER DESIGN for details.
Depending on the inductance, using inductances lower than 1µH results in a higher inductor current ripple. It can
be calculated as:
(5)
With:
V
IN
= Input Voltage
V
OUT
= Output Voltage
ƒ = Switching frequency, typ. 2.5 MHz
L = Inductance
Inductor Saturation Current
The inductor needs to be selected for its current rating. To pick the proper saturation current rating, the maximum
inductor current can be calculated as:
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