Datasheet

LM3668
www.ti.com SNVS449M –JUNE 2007–REVISED MAY 2013
ELECTRICAL CHARACTERISTICS
(1)(2)
Limits in standard typeface are for T
J
= +25°C. Limits in boldface type apply over the full operating ambient temperature
range (−40°C ≤ = T
A
≤ +85°C). Unless otherwise noted, specifications apply to the LM3668. V
IN
= 3.6V = EN, V
OUT
= 3.3V.
For V
OUT
= 4.5/5.0V, V
IN
= 4V.
Symbol Parameter Conditions Min Typ Max Units
V
FB
Feedback Voltage See
(2)
–3 3 %
I
LIM
Switch Peak Current Limit Open loop
(3)
1.6 1.85 2.05 A
I
SHDN
Shutdown Supply Current EN =0V 0.01 1 µA
I
Q_PFM
DC Bias Current in PFM No load, device is not switching
(FB forced higher than 45 60 µA
programmed output voltage)
I
Q_PWM
DC Bias Current in PWM PWM Mode, No Switching 600 750 µA
R
DSON(P)
Pin-Pin Resistance for PFET Switches P1 and P2 130 180 mΩ
R
DSON(N)
Pin-Pin Resistance for NFET Switches N1 and N2 100 150 mΩ
F
OSC
Internal Oscillator Frequency PWM Mode 1.9 2.2 2.5 MHz
F
SYNC
Sync Frequency Range V
IN
= 3.6V 1.6 2.7 MHz
V
IH
Logic High Input for EN,
1.1 V
MODE/SYNC pins
V
IL
Logic Low Input for EN, MODE/SYNC
0.4 V
pins
I
EN, MODE, SYNC
EN, MODE/SYNC pins Input Current 0.3 1 µA
(1) All voltage with respect to SGND.
(2) Min and Max limits are specified by design, test, or statistical analysis. Typical numbers are not ensured, but do represent the most
likely norm.
(3) Electrical Characteristics table reflects open loop data (FB = 0V and current drawn from SW pin ramped up until cycle by cycle current
limits is activated). Closed loop current limit is the peak inductor current measured in the application circuit by increasing output current
until output voltage drops by 10%.
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