TEA1202 Philips Semiconductors, TEA1202 Datasheet - Page 17

• Manufacturer Part Number: TEA1202
• Description: Battery power unit
• Manufacturer: Philips Semiconductors

Philips Semiconductors
External component selection
I
The performance of the TEA1202TS is not very sensitive
to inductance value. The best efficiency performance over
a wide load current range is achieved by using an
inductance of 6.8 H e.g. TDK SLF7032 or Coilcraft
DO1608 range.
DC/DC
The value of C1 strongly depends on the type of input
source. In general, a 100 F tantalum capacitor is
sufficient.
DC/DC
The value and type of C2 depends on the maximum output
current and the ripple voltage which is allowed in the
application. Low-ESR tantalum capacitors show good
results. The most important specification of C2 is its ESR,
which mainly determines output voltage ripple.
D
The Schottky diode is only used for short time during
takeover from N-type power MOSFET and P-type power
MOSFET and vice versa. Therefore, a medium-power
diode is sufficient in most applications e.g. Philips
PRLL5819.
F
The output voltage of the DC/DC converter is determined
by the resistors R1 and R2. The following conditions
apply:
Under these conditions, the output voltage can be
calculated by the formula:
2000 Jun 08
V
NDUCTOR
EEDBACK RESISTORS
IODE
O
Use a 1% accurate SMD type resistors only. If larger
body resistors are used, the capacitance on pin FB0 will
be too large, causing inaccurate operation.
Resistors R1 and R2 should have a maximum value of
50 k when connected in parallel. A higher value will
result in inaccurate operation.
Battery power unit
=
D1
V
INPUT CAPACITOR
OUTPUT CAPACITOR
ref
L1
1
+
R1
------- -
R2
R1
C1
AND
C2
R2
17
C
The maximum instantaneous current is set by the external
resistor R10. The preferred type is SMD, 1% accurate.
The connection of resistor R10 differs for each mode:
The average inductor current during limited current
operation also depends on the inductance value, input
voltage, output voltage and resistive losses in all
components in the power path. Ensure that
I
R
Optionally, a decoupling capacitor can be connected
between pin V
noise level of the output voltages of the LDO. The best
choice for C5 is a ceramic multilayer capacitor of
approximately 100 nF.
LDO
A typical LDO output capacitor is a ceramic multilayer
capacitor of 2.2 F, e.g. GRM40X5R225K6.3 of Murata.
The ESR of the output capacitor must be between
10 and 100 m to achieve stability and the specified
transient response.
lim
URRENT LIMITING RESISTOR
EFERENCE VOLTAGE DECOUPLING CAPACITOR
At upconversion: resistor R10 must be connected
between pins ILIM and UPOUT/DNIN; the current
limiting level is defined by:
At downconversion: resistor R10 must be connected
between pins ILIM and GND0; the current limiting level
is defined by:
< I
OUTPUT CAPACITORS
sat
(saturation current) of the inductor.
ref
I
and ground in order to achieve a lower
Iim
=
---------- -
R10
300
C3
R10
AND
I
Iim
C4
=
Objective specification
---------- -
R10
320
TEA1202TS
C5