Datasheet

LM3224
www.ti.com SNVS277C –DECEMBER 2004–REVISED MARCH 2013
Electrical Characteristics
(1)
Specifications in standard type face are for T
J
= 25°C and those with boldface type apply over the full Operating
Temperature Range ( T
J
= −40°C to +125°C). V
IN
= 2.7V, FSLCT = SHDN = V
IN
, and I
L
= 0A, unless otherwise specified.
Min Typ Max
Symbol Parameter Conditions Units
(1) (2) (1)
I
Q
Quiescent Current FB = 2V (Not Switching) 1.3 2.0 mA
V
SHDN
= 0V 0.1 2.0 µA
V
FB
Feedback Voltage 1.2285 1.26 1.2915 V
I
CL
(3)
Switch Current Limit V
IN
= 2.7V
(4)
1.9 2.45 2.8
V
IN
= 3V, V
OUT
= 8V 2.1 A
V
IN
= 3V, V
OUT
= 5V 2.2
%V
FB
/ΔV
IN
Feedback Voltage Line 2.7V ≤ V
IN
≤ 7V
0.085 0.15 %/V
Regulation
I
B
FB Pin Bias Current
(5)(6)
35 250 nA
I
SS
SS Pin Current 7.5 11 13 µA
V
SS
SS Pin Voltage 1.2090 1.2430 1.2622
V
IN
Input Voltage Range 2.7 7 V
g
m
Error Amp Transconductance ΔI = 5µA 40 87 135 µmho
A
V
Error Amp Voltage Gain 78 V/V
D
MAX
Maximum Duty Cycle 85 92.5 %
f
S
Switching Frequency FSLCT = Ground 450 615 750 kHz
FSLCT = V
IN
0.9 1.25 1.5 MHz
I
SHDN
Shutdown Pin Current V
SHDN
= 2.7V 2.4 5.0 µA
V
SHDN
= 0.3V 0.3 1.2
I
L
Switch Leakage Current V
SW
= 20V 0.2 8.0 µA
R
DSON
Switch R
DSON
V
IN
= 2.7V, I
SW
= 1A 0.15 0.4 Ω
Th
SHDN
Shutdown Threshold Output High 1.2 0.8 V
Output Low 0.8 0.3 V
UVP On Threshold 2.3 2.5 V
Off Threshold 2.6 2.7 V
(1) All limits ensured at room temperature (standard typeface) and at temperature extremes (bold typeface). All room temperature limits are
100% production tested. All limits at temperature extremes are ensured via correlation using standard Statistical Quality Control (SQC)
methods. All limits are used to calculate Average Outgoing Quality Level (AOQL).
(2) Typical numbers are at 25°C and represent the most likely norm.
(3) Duty cycle affects current limit due to ramp generator.
(4) Current limit at 0% duty cycle. See Typical Performance Characteristics for Switch Current Limit vs. V
IN
(5) Bias current flows into FB pin.
(6) The FB pin should never exceed V
IN
.
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