LTC1539 View Datasheet(PDF) - Linear Technology
Part Name
Description
MFG CO.
LTC1539
Linear Technology
'LTC1539' PDF : 32 Pages View PDF
LTC1538-AUX/LTC1539
TYPICAL PERFORMANCE CHARACTERISTICS
Auxiliary Regulator Sink
Current Available
20
15
10
5
0
0 2 4 6 8 10 12 14 16
AUX DR VOLTAGE (V)
1538/39 • G19
Auxiliary Regulator PSRR
100
90
80
IL = 10mA
70
60
IL = 100mA
50
40
30
20
10
0
10
100
FREQUENCY (kHz)
1000
1538/39 • G20
PIN FUNCTIONS
VIN: Main Supply Pin. Must be closely decoupled to the
IC’s signal ground pin.
INTVCC/5V STANDBY: Output of the Internal 5V Regulator
and the EXTVCC Switch. The driver and control circuits are
powered from this voltage. Must be closely decoupled to
power ground with a minimum of 2.2µF tantalum or
electrolytic capacitor. The INTVCC regulator remains on
when both RUN/SS1 and RUN/SS2 are low. Refer to the
LTC1438/LTC1439 for applications which do not require a
5V standby regulator.
EXTVCC: External Power Input to an Internal Switch. This
switch closes and supplies INTVCC, bypassing the internal
low dropout regulator whenever EXTVCC is higher than 4.8V.
Connect this pin to VOUT of the controller with the higher
output voltage. Do not exceed 10V on this pin. See EXTVCC
connection in Applications Information section.
BOOST 1, BOOST 2: Supplies to the Topside Floating Drivers.
The bootstrap capacitors are returned to these pins. Voltage
swing at these pins is from INTVCC to VIN + INTVCC.
SW1, SW2: Switch Node Connections to Inductors. Volt-
age swing at these pins is from a Schottky diode (external)
voltage drop below ground to VIN.
SGND: Small Signal Ground. Common to both controllers,
must be routed separately from high current grounds to
the (–) terminals of the COUT capacitors.
PGND: Driver Power Ground. Connects to sources of
bottom N-channel MOSFETs and the (–) terminals of CIN.
SENSE – 1, SENSE – 2: Connects to the (–) input for the
current comparators. SENSE– 1 is internally connected to
the first controllers VOUT sensing point preventing true
remote output voltage sensing operation. The first con-
troller can only be used as a 3.3V or 5.0V regulator
controlled by the VPROG1 pin. The second controller can be
set to a 3.3V, 5.0V or an adjustable regulator controlled by
the VPROG2 pin (see Table 1).
Table 1. Output Voltage Table
CONTROLLER 1
CONTROLLER 2
LTC1538-AUX
LTC1539
5V or 3.3V Only, Secondary Feedback Loop
Adjustable Only
Remote Sensing
5V/3.3V/Adjustable
Remote Sensing
POR1 Output
7
Share Link: 