LT1308BCS8#TRPBF Linear Technology, LT1308BCS8#TRPBF Datasheet - Page 15

• Manufacturer Part Number: LT1308BCS8#TRPBF
• Description: IC DC/DC CONV SINGLE CELL 8-SOIC
• Manufacturer: Linear Technology
• Type: Step-Up (Boost)r

Specifications of LT1308BCS8#TRPBF

• Internal Switch(s): Yes
• Synchronous Rectifier: No
• Number Of Outputs: 1
• Voltage - Output: 5V
• Current - Output: 1A
• Frequency - Switching: 600kHz
• Voltage - Input: 1 ~ 10 V
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Surface Mount
• Package / Case: 8-SOIC (3.9mm Width)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Power - Output: -

APPLICATIONS INFORMATION
GSM AND CDMA PHONES
The LT1308A/LT1308B are suitable for converting a single
Li-Ion cell to 5V for powering RF power stages in GSM or
CDMA phones. Improvements in the LT1308A/LT1308B
error amplifi ers allow external compensation values to be
reduced, resulting in faster transient response compared
to the LT1308. The circuit of Figure 24 (same as Figure 1,
printed again for convenience) provides a 5V, 1A output
from a Li-Ion cell. Figure 25 details transient response at
the LT1308A operating at a V
voltage in Burst Mode operation can be seen at 10mA
load. Figure 26 shows transient response of the LT1308B
under the same conditions. Note the lack of Burst Mode
ripple at 10mA load.
CURRENT
C1: AVX TAJC476M010
C2: AVX TPSD227M006
LOAD
500mV/DIV
Li-Ion
CELL
Figure 24. Li-Ion to 5V Boost Converter Delivers 1A
500mA
1A/DIV
+
50mA
V
Figure 23. Load Step Response with 10μF X5R
Ceramic Output Capacitor and C
OUT
I
L1
SHUTDOWN
C1
47μF
D1: IR 10BQ015
L1: MURATA LQH6N4R7
SHDN
V
V
IN
C
47k
LT1308B
100pF
200μs/DIV
4.7μH
L1
IN
of 4.2V, 3.6V and 3V. Ripple
GND
SW
FB
D1
PL
R1
309k
R2
100k
+
1308 F23
1308A/B F24
C2
220μF
5V
1A
V
V
V
V
IN
IN
V
IN
IN
V
IN
= 4.2V
= 3.6V
IN
10mA
I
= 4.2V
= 3.6V
V
V
V
LOAD
I
= 3V
V
V
V
LOAD
= 3V
1mA
OUT
OUT
OUT
OUT
OUT
OUT
1A
Figure 25. LT1308A Li-Ion to 5V Boost Converter
Transient Response to 1A Load Step
Figure 26. LT1308B Li-Ion to 5V Boost
Converter Transient Response to 1A Load Step
1A
V
200mV/DIV
V
200mV/DIV
OUT
OUT
TRACES =
TRACES =
LT1308A/LT1308B
100μs/DIV
200μs/DIV
1308 F26
1308 F25
15
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