SC4521 View Datasheet(PDF) - Semtech Corporation
Part Name
Description
MFG CO.
'SC4521' PDF : 18 Pages View PDF
SC4521
POWER MANAGEMENT
Electrical Characteristics (Cont.)
Unless specified: VIN = 12V, VCOMP = 0.8V, VBST = VIN + 5V, EN = tied to VIN, SW = open.
TA = TJ = -40°C to 125°C.
Parameter
Symbol
Conditions
FB Input Current
IFB
Feedback Voltage
VFB
Feedback Voltage Line
Regulation
4.4V < VIN < 24V(1)
FB to VCOMP Voltage Gain(2)
FB to VCOMP
Transconductance(2)
0.9V ≤ VCOMP ≤ 2.0V
∆ ICOMP = ± 10µA
VCOMP Pin Source Current
VCOMP Pin Sink Current
VCOMP Pin to Switch Current
Transconductance
VFB = 0.6V
VFB = 1.0V
VCOMP = 1.25V
VCOMP Pin Maximum Switching
Threshold
Duty cycle = 0%
VCOMP OCP Threshold
VCOMP Hiccup Retry Threshold
Maximum Switch Duty Cycle
DMAX
VCOMP rising
VCOMP falling
VCOMP = 1.2V, ISW = 400mA
Min
0.784
Typ
-0.25
0.8
+3
Max
-1
0.816
Units
µA
V
mV/V
150 350
V/V
500 850 1300 µMho
70
110
µA
-70 -110
µA
4.3
A/V
0.6
V
2
V
0.25
V
85
%
Minimum Boost Voltage Above
Switch(2)
2.7
V
Boost Current
Enable Input Threshold Voltage
VETH
Enable Output Bias Current
IEOL
IEOH
Soft Start Charging Current (3)
ISS
Soft Start Discharging Current
ISS
ISW = 1A
ISW = 3A
EN = 50mV below threshold
EN = 50mV below threshold
VSS = 0
10
15
mA
30
45
1.1 1.27 1.5
V
8
µA
10
µA
16
µA
-2
mA
Notes:
(1) The required minimum input voltage for a regulated output depends on the output voltage and load condition.
(2) Guaranteed by design.
(3) See Application Information.
2007 Semtech Corp.
3
www.semtech.com
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