OMO ElectronicOMO Electronic
Expand menu
Hello, Sign inMy Account
0 Cart

LT1308BCS8#PBF

P1-P3P4-P6P7-P9P10-P12P13-P15P16-P18P19-P20
LT1308A/LT1308B
4
1308abfb
ELECTRICAL CHARACTERISTICS
LT1308B
3.3V Output Effi ciency
LT1308A
3.3V Output Effi ciency
LT1308A
5V Output Effi ciency
The l denotes the specifi cations which apply over the full operating temperature
range, otherwise specifi cations are at T
A
= 25°C. Industrial Grade –40°C to 85°C. V
IN
= 1.2V, V
SHDN
= V
IN
, unless otherwise noted.
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
f
OSC
Switching Frequency
l
500 600 750 kHz
Maximum Duty Cycle
l
82 90 %
Switch Current Limit Duty Cycle = 30% (Note 4) 2 3 4.5 A
Switch V
CESAT
I
SW
= 2A (25°C, –40°C), V
IN
= 1.5V
I
SW
= 2A (85°C), V
IN
= 1.5V
290
330
350
400
mV
mV
Burst Mode Operation Switch Current Limit
(LT1308A)
V
IN
= 2.5V, Circuit of Figure 1 400 mA
Shutdown Pin Current V
SHDN
= 1.1V
V
SHDN
= 6V
V
SHDN
= 0V
l
l
2
20
0.01
5
35
0.1
µA
µA
µA
LBI Threshold Voltage
l
196
193
200
200
204
207
mV
mV
LBO Output Low I
SINK
= 50µA
l
0.1 0.25 V
LBO Leakage Current V
LBI
= 250mV, V
LBO
= 5V
l
0.01 0.1 µA
LBI Input Bias Current (Note 5) V
LBI
= 150mV 33 100 nA
Low-Battery Detector Gain 3000 V/V
Switch Leakage Current V
SW
= 5V
l
0.01 10 µA
Note 1: Stresses beyond those listed under Absolute Maximum Ratings
may cause permanent damage to the device. Exposure to any Absolute
Maximum Rating condition for extended periods may affect device
reliability and lifetime.
Note 2: The LT1308ACS8, LT1308ACF, LT1308BCS8 and LT1308BCF are
designed, characterized and expected to meet the industrial temperature
limits, but are not tested at –40°C and 85°C. I grade devices are
guaranteed over the –40°C to 85°C operating temperature range.
Note 3: Bias current fl ows into FB pin.
Note 4: Switch current limit guaranteed by design and/or correlation to
static tests. Duty cycle affects current limit due to ramp generator (see
Block Diagram).
Note 5: Bias current fl ows out of LBI pin.
Note 6: Connect the four GND pins (Pins 4–7) together at the device.
Similarly, connect the three SW pins (Pins 8–10) together and the two V
IN
pins (Pins 11, 12) together at the device.
TYPICAL PERFORMANCE CHARACTERISTICS
LOAD CURRENT (mA)
95
90
85
80
75
70
65
60
55
50
1 100 1000
1308A/B G01
10
EFFICIENCY (%)
V
IN
= 1.8V
V
IN
= 2.5V
V
IN
= 1.2V
LOAD CURRENT (mA)
95
90
85
80
75
70
65
60
55
50
1 100 1000
1308A/B G02
10
EFFICIENCY (%)
V
IN
= 1.8V
V
IN
= 2.5V
V
IN
= 1.2V
LOAD CURRENT (mA)
1
EFFICIENCY (%)
95
90
85
80
75
70
65
60
55
50
10 100 1000
1308A/B G03
V
IN
= 4.2V
V
IN
= 2.5V
V
IN
= 3.6V
V
IN
= 1.5V
LT1308A/LT1308B
5
1308abfb
TYPICAL PERFORMANCE CHARACTERISTICS
SHDN Pin Bias Current vs Voltage
FB, LBI Bias Current vs
Temperature
Low Battery Detector Reference
vs Temperature
Oscillator Frequency vs
Temperature
LT1308A Quiescent Current vs
Temperature
Feedback Pin Voltage vs
Temperature
LT1308B
12V Output Effi ciency
Switch Current Limit vs
Duty Cycle
Switch Saturation Voltage
vs Current
LOAD CURRENT (mA)
90
85
80
75
70
65
60
55
50
1 100 1000
1308A/B G04
10
EFFICIENCY (%)
V
IN
= 5V
V
IN
= 3.3V
DUTY CYCLE (%)
0
CURRENT LIMIT (A)
3.0
3.5
80
1308 • G05
2.5
2.0
20
40
60
100
4.0
SWITCH CURRENT (A)
0
SWITCH V
CESAT
(mV)
2.0
85°C
1308 G06
0.5
1.0
1.5
500
400
300
200
100
0
25°C
–40°C
SHDN PIN VOLTAGE (V)
0
SHDN PIN CURRENT (µA)
50
40
30
20
10
0
8
1308 G07
2
4
6
10
–40°C
25°C
85°C
TEMPERATURE (°C)
–50 –25
BIAS CURRENT (nA)
05025
75
100
1308 • G08
80
70
60
50
40
30
20
10
0
LBI
FB
TEMPERATURE (°C)
–50 –25
V
REF
(mV)
05025
75
100
1308 • G09
203
202
201
200
199
198
197
196
195
TEMPERATURE (°C)
–50 –2.5
FREQUENCY (kHz)
05025
75
100
1308 • G10
800
750
700
650
600
550
500
450
400
TEMPERATURE (°C)
–50 –25
QUIESCENT CURRENT (µA)
05025
75
100
1308 • G11
180
170
160
150
140
130
120
110
100
TEMPERATURE (°C)
–50 –25
V
FB
(V)
05025
75
100
1308 • G12
1.25
1.24
1.23
1.22
1.21
1.20
1.19
1.18
LT1308A/LT1308B
6
1308abfb
PIN FUNCTIONS
V
C
(Pin 1/Pin 1): Compensation Pin for Error Amplifi er.
Connect a series RC from this pin to ground. Typical values
are 47k and 100pF. Minimize trace area at V
C
.
FB (Pin 2/Pin 2): Feedback Pin. Reference voltage is
1.22V. Connect resistive divider tap here. Minimize trace
area at FB. Set V
OUT
according to:
V
OUT
= 1.22V(1 + R1/R2).
SHDN (Pin 3/Pin 3): Shutdown. Ground this pin to turn
off switcher. To enable, tie to 1V or more. SHDN does
not need to be at V
IN
to enable the device.
GND (Pin 4/Pins 4, 5, 6, 7): Ground. Connect directly
to local ground plane. Ground plane should enclose all
components associated with the LT1308. PCB copper
connected to these pins also functions as a heat sink. For
the TSSOP package, connect all pins to ground copper
to get the best heat transfer. This keeps chip heating to
a minimum.
SW (Pin 5/Pins 8, 9, 10): Switch Pins. Connect induc-
tor/diode here. Minimize trace area at these pins to keep
EMI down. For the TSSOP package, connect all SW pins
together at the package.
V
IN
(Pin 6/Pins 11, 12): Supply Pins. Must have local
bypass capacitor right at the pins, connected directly to
ground. For the TSSOP package, connect both V
IN
pins
together at the package.
LBI (Pin 7/Pin 13): Low-Battery Detector Input. 200mV
reference. Voltage on LBI must stay between –100mV
and 1V. Low-battery detector does not function with
SHDN pin grounded. Float LBI pin if not used.
LBO (Pin 8/Pin 14): Low-Battery Detector Output. Open
collector, can sink 50µA. A 220k pull-up is recommend-
ed. LBO is high impedance when SHDN is grounded.
(SO/TSSOP)
P1-P3P4-P6P7-P9P10-P12P13-P15P16-P18P19-P20

LT1308BCS8#PBF

Mfr. #:
Buy LT1308BCS8#PBF
Manufacturer:
Analog Devices / Linear Technology
Description:
Switching Voltage Regulators 1x Cell Hi C uP 600kHz Boost DC/DC Conv
Lifecycle:
New from this manufacturer.
Delivery:
DHL FedEx Ups TNT EMS
Payment:
T/T Paypal Visa MoneyGram Western Union

Products related to this Datasheet