Datasheet

LM26480
SNVS543I –JANUARY 2008–REVISED MAY 2013 www.ti.com
Buck Converters SW1, SW2
Unless otherwise noted, V
IN
= 3.6V, C
IN
= 10 µF, C
OUT
= 10 µF, L
OUT
= 2.2 µH. Typical values and limits appearing in normal
type apply for T
J
= 25°C. Limits appearing in boldface type apply over the entire junction temperature range for operation,
−40°C to +125°C. (
(1) (2)(3)(4)(5)(6)
Symbol Parameter Conditions Min Typ Max Units
V
FB
(6)
Feedback Voltage −3 +3 %
2.8 < V
IN
< 5.5
Line Regulation 0.089 %/V
I
O
=10 mA
V
OUT
Load Regulation 100 mA < I
O
< I
MAX
0.0013 %/mA
Eff Efficiency Load Current = 250 mA 96 %
I
SHDN
Shutdown Supply Current EN is de-asserted 0.01 1 µA
Default oscillator frequency = 2.0
1.6 2.0 2.4
MHz
f
OSC
Internal Oscillator Frequency MHz
Default oscillator frequency = 2.1
1.7 2.1 2.5
MHz
Buck1 Peak Switching Current Limit 2.0 2.4
I
PEAK
A
Buck2 Peak Switching Current Limit 2.0 2.4
No load PFM Mode 33 µA
I
q
Quiescent Current “On”
No load PWM Mode (Forced PWM) 2 mA
R
DSON
(P) Pin-Pin Resistance PFET 200 400 mΩ
R
DSON
(N) Pin-Pin Resistance NFET 180 400 mΩ
T
ON
Turn On Time Start up from shut-down 500 µsec
C
IN
Input Capacitor Capacitance for stability 10 µF
C
O
Output Capacitor Capacitance for stability 10 µF
(1) All voltages are with respect to the potential at the GND pin.
(2) Min and Max limits are speficified by design, test, or statistical analysis. Typical numbers represent the most likely norm.
(3) C
IN
, C
OUT
: Low-ESR Surface-Mount Ceramic Capacitors (MLCCs) used in setting electrical characteristics.
(4) The device maintains a stable, regulated output voltage without a load.
(5) Quiescent current is defined here as the difference in current between the input voltage source and the load at V
OUT
.
(6) V
IN
≥ V
OUT
+ R
DSON
(P) (I
OUT
+ 1/2 I
RIPPLE
). If these conditions are not met, voltage regulation will degrade as load increases.
I/O Electrical Characteristics
Unless otherwise noted: Typical values and limits appearing in normal type apply for T
J
= 25°C. Limits appearing in boldface
type apply over the entire junction temperature range for operation, T
J
= −40°C to +125°C.
Limit
Symbol Parameter Conditions Units
Min Max
V
IL
Input Low Level 0.4 V
V
IH
Input High Level 0.7*VDD V
Power On Reset Threshold/Function (POR)
Symbol Parameter Conditions Min Typ Max Units
Default = 60 mS 60 mS
nPOR = Power on reset for Buck1 and
nPOR
Buck2
Default = 130 µS 130 µS
V
BUCK1
AND V
BUCK2
rising 92
nPOR Percentage of Target voltage Buck1 or
%
Threshold Buck2
V
BUCK1
OR V
BUCK2
falling 82
V
OL
Output Level Low Load = I
OL
= 500 µA 0.23 0.5 V
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