TC1303B Datasheet, PDF (5/30 Pages) Microchip Technology – 500 mA Synchronous Buck Regulator, + 300 mA LDO with Power-Good Output

TC1303B
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
Synchronous Buck Regulator (V_OUT1)
Adjustable Output Voltage Range V_OUT1
Adjustable Reference Feedback
Voltage (V_FB1)
V_FB1
Feedback Input Bias Current
(I_FB1)
I_VFB1
Output Voltage Tolerance Fixed
(V_OUT1)
V_OUT1
Line Regulation (V_OUT1)
V_LINE-REG
Load Regulation (V_OUT1)
V_LOAD-REG
0.8
0.78
—
-2.5
—
—
—
0.8
-1.5
±0.3
0.2
0.2
4.5
0.82
—
+2.5
—
—
V
V
nA
%
Note 2
%/V V_IN =V_R+1V to 5.5V,
I_LOAD = 100 mA
%
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
Start Up Time
R_DSon P-CHANNEL
R_DSon N-CHANNEL
L_X Pin Leakage Current
F_OSC
T_SS
R_DSon-P
R_DSon-N
I_LX
Positive Current Limit Threshold
LDO Output (V_OUT2)
Output Voltage Tolerance (V_OUT2)
Temperature Coefficient
Line Regulation
Load Regulation, V_OUT2 ≥ 2.5V
Load Regulation, V_OUT2 < 2.5V
Dropout Voltage V_OUT2 > 2.5V
+I_LX(MAX)
V_OUT2
TCV_OUT
ΔV_OUT2/
ΔV_IN
ΔV_OUT2/
I_OUT2
ΔV_OUT2/
I_OUT2
V_IN – V_OUT2
Power Supply Rejection Ratio
PSRR
1.6
—
—
—
-1.0
—
-2.5
—
-0.2
-0.75
-0.90
—
—
Output Noise
eN
—
2.0
2.4
0.5
—
450
650
450
650
±0.01
1.0
700
—
MHz
ms
mΩ
mΩ
μA
mA
T_R = 10% to 90%
I_P=100 mA
I_N=100 mA
SHDN = 0V, V_IN = 5.5V, L_X = 0V,
L_X = 5.5V
±0.3
25
±0.02
0.1
0.1
137
205
62
1.8
+2.5
—
+0.2
%
ppm/°C
%/V
Note 2
Note 3
(V_R+1V) ≤ V_IN ≤ 5.5V
+0.75
%
I_OUT2 = 0.1 mA to 300 mA (Note 4)
+0.90
%
I_OUT2 = 0.1 mA to 300 mA (Note 4)
300
mV I_OUT2 = 200 mA (Note 5)
500
I_OUT2 = 300 mA
—
dB
f ≤ 100 Hz, I_OUT1 = I_OUT2 = 50 mA,
C_IN = 0 µF
—
µV/(Hz)^½ f ≤ 1 kHz, I_OUT2 = 50 mA,
SHDN1 = GND
Output Short Circuit Current
(Average)
I_OUTsc2
—
240
—
mA
R_LOAD2 ≤ 1Ω
Note 1:
2:
3:
4:
5:
6:
7:
8:
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.
V_RX is the regulator output voltage setting.
TCV_OUT2 = ((V_OUT2max – V_OUT2min) * 10⁶)/(V_OUT2 * D_T).
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.
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.
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.
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.
V_IN1 and V_IN2 are supplied by the same input source.
© 2005 Microchip Technology Inc.
DS21949A-page 5