Datasheet

TC1303A/TC1303B/TC1303C/TC1304
DS21949C-page 8 © 2008 Microchip Technology Inc.
Synchronous Buck Regulator (V
OUT1
)
Adjustable Output Voltage Range V
OUT1
0.8 — 4.5 V
Adjustable Reference Feedback
Voltage (V
FB1
)
V
FB1
0.78 0.8 0.82 V
Feedback Input Bias Current
(
IFB1
)
I
VFB1
—-1.5— nA
Output Voltage Tolerance Fixed
(V
OUT1
)
V
OUT1
-2.5 ±0.3 +2.5 % Note 2
Line Regulation (V
OUT1
)V
LINE-REG
— 0.2 — %/V V
IN
=V
R
+1V to 5.5V,
I
LOAD
= 100 mA
Load Regulation (V
OUT1
)V
LOAD-REG
—0.2— %V
IN
=V
R
+1.5V, I
LOAD
= 100 mA to
500 mA (Note 1)
Dropout Voltage V
OUT1
V
IN
– V
OUT1
— 280 — mV I
OUT1
= 500 mA, V
OUT1
=3.3V
(Note 5)
Internal Oscillator Frequency F
OSC
1.6 2.0 2.4 MHz
Start Up Time T
SS
—0.5— msT
R
= 10% to 90%
R
DSon
P-Channel R
DSon-P
— 450 — mΩ I
P
=100 mA
R
DSon
N-Channel R
DSon-N
— 450 — mΩ I
N
=100 mA
L
X
Pin Leakage Current I
LX
-1.0 ±0.01 1.0 μA SHDN = 0V, V
IN
= 5.5V, L
X
= 0V,
L
X
= 5.5V
Positive Current Limit Threshold +I
LX(MAX)
— 700 — mA
LDO Output (V
OUT2
)
Output Voltage Tolerance (V
OUT2
)V
OUT2
-2.5 ±0.3 +2.5 % Note 2
Temperature Coefficient TCV
OUT
— 25 — ppm/°C Note 3
Line Regulation ∆V
OUT2
/
∆V
IN
-0.2 ±0.02 +0.2 %/V (V
R
+1V) ≤ V
IN
≤ 5.5V
Load Regulation, V
OUT2
≥ 2.5V ∆V
OUT2
/
I
OUT2
-0.75 -0.08 +0.75 %I
OUT2
= 0.1 mA to 300 mA (Note 4)
Load Regulation, V
OUT2
< 2.5V ∆V
OUT2
/
I
OUT2
-0.9 -0.18 +0.9 %I
OUT2
= 0.1 mA to 300 mA (Note 4)
Dropout Voltage V
OUT2
> 2.5V V
IN
– V
OUT2
— 137
205
300
500
mV I
OUT2
= 200 mA (Note 5)
I
OUT2
= 300 mA
Power Supply Rejection Ratio PSRR — 62 — dB f ≤ 100 Hz, I
OUT1
= I
OUT2
= 50 mA,
C
IN
= 0 µF
Output Noise eN — 1.8 — µV/(Hz)
½
f ≤ 1 kHz, I
OUT2
=50mA,
SHDN1
=GND
DC CHARACTERISTICS (CONTINUED)
Electrical Characteristics: V
IN1
=V
IN2
= SHDN1,2 = 3.6V, C
OUT1
=C
IN
= 4.7 µF, C
OUT2
=1µF, L = 4.7 µH, V
OUT1
(ADJ) = 1.8V,
I
OUT1
= 100 mA, I
OUT2
= 0.1 mA T
A
= +25°C. Boldface specifications apply over the T
A
range of -40°C to +85°C.
Parameters Sym Min Typ Max Units Conditions
Note 1: The Minimum V
IN
has to meet two conditions: V
IN
≥ 2.7V and V
IN
≥ V
RX
+ V
DROPOUT,
V
RX
= V
R1
or V
R2
.
2: V
RX
is the regulator output voltage setting.
3: TCV
OUT2
= ((V
OUT2max
– V
OUT2min
) * 10
6
)/(V
OUT2
* D
T
).
4: Regulation is measured at a constant junction temperature using low duty-cycle pulse testing. Load regulation is tested
over a load range from 0.1 mA to the maximum specified output current.
5: Dropout voltage is defined as the input-to-output voltage differential at which the output voltage drops 2% below its
nominal value measured at a 1V differential.
6: The maximum allowable power dissipation is a function of ambient temperature, the maximum allowable junction
temperature and the thermal resistance from junction to air. (i.e. T
A
, T
J
, θ
JA
). Exceeding the maximum allowable power
dissipation causes the device to initiate thermal shutdown.
7: The integrated MOSFET switches have an integral diode from the L
X
pin to V
IN
, and from L
X
to P
GND
. In cases where
these diodes are forward-biased, the package power dissipation limits must be adhered to. Thermal protection is not
able to limit the junction temperature for these cases.
8: V
IN1
and V
IN2
are supplied by the same input source.