NCP1526
http://onsemi.com
13
Table 3. List of Inductors
FDK MIPW3226 series
TDK
VLF3010AT series
TFC252005 series
Taiyo Yuden LQ CBL2012
Coil craft
DO1605−T series
LPO3008
Output capacitor selection
Selecting the proper output capacitor is based on the
desired output ripple voltage. Ceramic capacitors with low
ESR values will have the lowest output ripple voltage and
are strongly recommended. The output capacitor requires
either an X7R or X5R dielectric.
The output ripple voltage in PWM mode is given by:
DV
out
+ DI
L
ǒ
1
4 f
sw
C
out
) ESR
Ǔ
Table 4. List of Output Capacitors
Murata GRM188R60J475KE 4.7 mF
GRM21BR71C475KA
GRM188R60OJ106ME 10 mF
Taiyo Yuden JMK212BY475MG 4.7 mF
JMK212BJ106MG 10 mF
TDK C2012X5ROJ475KB 4.7 mF
C1632X5ROJ475KT
C2012X5ROJ106K 10 mF
OUTPUT VOLTAGE OPTIONS AVAILABLE UPON
REQUEST
DC/DC Converter
Fixed Output Voltage (V)
0.9
1.0
1.1
1.2
1.3
1.4
1.5
1.6
1.7
1.8
1.9
2.5
2.7
3.0
3.3
LDO Operation
Voltage Regulator V1
V1 is a 2.80 V, 3% low drop voltage regulator dedicated
to RF sensitive module. It can deliver up to 150 mA and is
totally protected against short to ground (current
limitation) and overtemperature (thermal shutdown circuit
with hysteresis).
The PSRR of the reference is in excess of 67 dB at
1.0 kHz. The output of the V1 requires a 1.0 mF capacitor
for stability. An additional 100 nF capacitor is necessary on
the BYPASS pin for a low output noise. If the BYPASS pin
is supporting an additional load, the stability and
performance of the V1 will be diminished. Since the input
voltage can go as low as 3.0 V, the reference output will be
affected and can drop as low as 150 mV below the input
voltage at 150 mA output current. During this low dropout,
the PSRR of the reference is reduced. V1 is active when
logic high is applied to the EN2 pin. It is turned off by a
logic low on the EN2 pin.
Reference Bypass Capacitor Node (Bypass)
An optional 100 nF BYPASS capacitor creates a low pass
filter for LDO noise reduction. The output voltage noise is
45 mV
RMS
with C
BYPASS
= 0.1 mF and C
OUT
= 1.0 mF. If the
BYPASS pin is supporting an additional load, the stability
and performance of the NCP1526 will be diminished.
Current Limiting
The output voltage regulator limits the output current to
I
SC
= 300 mA (typ). If the LDO output current exceeds I
SC
,
the output voltage drops.
Shutdown Mode
When the EN2 pin has a voltage applied of less than
0.4 V, the output voltage regulator will be disabled. In
shutdown mode, the internal reference and most of the
control circuitries are turned off. Therefore, the typical
current consumption will be 0.2 mA (typical value).
Applying a voltage above 1.2 V to EN2 pin will enable the
LDO for normal operation.
OUTPUT VOLTAGE OPTIONS AVAILABLE UPON
REQUEST
LDO
Fixed Output Voltage (V)
2.5
2.6
2.7
2.8
2.85
3.0
3.1
3.3
