LTC3125EDCB#TRPBF Linear Technology, LTC3125EDCB#TRPBF Datasheet - Page 12

• Manufacturer Part Number: LTC3125EDCB#TRPBF
• Description: IC DC/DC CONV STP-UP 1.2A 8-DFN
• Manufacturer: Linear Technology
• Type: Step-Up (Boost)r

Specifications of LTC3125EDCB#TRPBF

• Internal Switch(s): Yes
• Synchronous Rectifier: Yes
• Number Of Outputs: 1
• Voltage - Output: 2 ~ 5.25 V
• Current - Output: 1.2A
• Frequency - Switching: 1.6MHz
• Voltage - Input: 1.8 ~ 5.5 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 8-DFN
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Power - Output: -

LTC3125
APPLICATIONS INFORMATION
AVERAGE INPUT ILIMIT PROGRAMMING RESISTOR
SELECTION
The input current limit is user programmable by selection
of an external resistor, R
the resistor as close to the pin as possible to minimize
capacitance and noise pick-up. Resistor tolerance directly
affects the current limit accuracy so it must be factored in
to the application requirements. Table 3 shows standard
resistors for typical current limit values. Also refer to the
graph, “Average Input Current vs R
Performance Characteristics section of this datasheet.
TYPICAL APPLICATIONS
12
PC CARD V
1000mA MAX
3.3V ±10%
PC Card (3.3V/1000mA Maximum) 4.5V Output, GSM Pulsed Load
V
CC
IN
10μF
CER
OFF ON
22.6k
V
SHDN
PROG
CS
IN
PROG
LTC3125
2.7μH*
GND
. It is important to locate
V
**VISHAY 592D228X6R3X220H
SW
OUT
*WURTH 7440420027
FB
PROG
2.74M
1M
”, in the Typical
3125 TA03a
2200μF**
55mΩ
TANT
V
4.5V, 2A PULSED LOAD
(577μs PW, 4.6ms PERIOD)
2
OUT
Table 3.
For most applications the loss in accuracy from standard
1% resistors is tolerated but for critical applications the
use of 0.1% resistors is recommended.
STANDARD 1% RESISTOR VALUE
22.1
24.9
28.0
29.4
31.6
37.4
54.9
71.5
82.5
(K)
INPUT CURRENT
LOAD CURRENT
100mV/DIV
500mA/DIV
2A/DIV
V
OUT
V
V
C
L = 2.7μH
R
IN
OUT
OUT
PROG
= 3.3V
V
Waveforms of Input Current,
= 4.5V
= 4.4mF
OUT
= 22.6k
for Pulsed Load Current
TYPICAL APPLICATION
INPUT LIMIT (A)
1ms/DIV
1.001
0.890
0.791
0.750
0.699
0.588
0.393
0.295
0.252
3125 TA03b
3125fa