SC1410ACQSTRT Semtech, SC1410ACQSTRT Datasheet - Page 5

• Manufacturer Part Number: SC1410ACQSTRT
• Description: IC, BATTERY CHARGER, 1.5A, QSOP-16
• Manufacturer: Semtech

Specifications of SC1410ACQSTRT

• Battery Type: Li-Ion, NiCd, NiMH
• Input Voltage: 18V
• Battery Charge Voltage: 8V
• Charge Current Max: 1.5A
• Battery Ic Case Style: QSOP
• No. Of Pins: 16
• No. Of Series Cells: 1
• Output Current: 1.5A
• Output Voltage: 2 to 18V
• Operating Supply Voltage (min): 7V
• Operating Temp Range: 0C to 70C
• Package Type: QSOP
• Mounting: Surface Mount
• Pin Count: 16
• Operating Temperature Classification: Commercial
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

The SC1410A is a current mode, buck converter which
operates in constant current (CC) and constant voltage
(CV) modes. There are two feedback mechanisms, a frac-
tion of the output voltage is sensed at OVP and the out-
put current is sensed by RS1. When either or both of
these feedback mechanisms are implemented, the loops
act to maintain a nearly constant voltage of VREF at the
PROG pin.
In CC mode, the current amplifier CA1 and the sense resis-
tor RS1 combine to generate a program current (I
output current ratio of 500 A/A. The programmed output
current is therefore given by :-
I
I
or
R
where
BAT
BAT
POWER MANAGEMENT
Block Diagram
Theory of Operation
PROG
2006 Semtech Corp.
is
in
2000
Amps,
. 4
I
BAT
93
I
PROG
R
PROG
2
R
in
. 2
VC
PROG
k
465
1410 SCH22
VSW
VCC
0.7V
VBAT
60k
+
-
-
+
-
+
SHUTDOWN
CA2
PROG
-
+
SLOPE
COMP.
500kHz
OSCILLATOR
) to
C
PROG
5
As the voltage at the OVP pin rises, reaching V
voltage amplifier VA sources current into R
I
only a few mV increase at the OVP pin.
The SR latch is set by the 500kHz oscillator, turning on
the output transistor (QSW). The outer control loop of CA2,
the 60k resistor and external components on the VC pin
sets a DC level against which the inner loop DC and AC
current information generated by RS1, CA1 and the buffer
and divider is compared. When the voltage at the + pin of
the comparator exceeds the DC level at the - pin, the latch
is reset and QSW turned off.
S
R
BAT
R
. I
Q
PROG
-
+
BAT
will go from full programmed current to zero with
1k
PROG
I
PROG
IPROG
IBAT
= 500uA/A
CA1
VA
QSW
+
-
+
-
VREF
2.465V
RS1
VCC
BOOST
SW
SENSE
BAT
OVP
SC1410A
www.semtech.com
PROG
, reducing
REF
, the