© 2008 Microchip Technology Inc.
DS21949C-page 1
TC1303A/TC1303B/
TC1303C/TC1304
Features
• Dual-Output Regulator (500 mA Buck Regulator
and 300 mA Low-Dropout Regulator)
• Power-Good Output with 300 ms Delay
• Total Device Quiescent Current = 65 µA, Typical
• Independent Shutdown for Buck and LDO
Outputs (TC1303)
• Both Outputs Internally Compensated
• Synchronous Buck Regulator:
- Over 90% Typical Efficiency
- 2.0 MHz Fixed-Frequency PWM
(Heavy Load)
- Low Output Noise
- Automatic PWM to PFM mode transition
- Adjustable (0.8V to 4.5V) and Standard
Fixed-Output Voltages (0.8V, 1.2V, 1.5V,
1.8V, 2.5V, 3.3V)
• Low-Dropout Regulator:
- Low-Dropout Voltage = 137 mV Typical @
200 mA
- Standard Fixed-Output Voltages
(1.5V, 1.8V, 2.5V, 3.3V)
• Power-Good Function:
- Monitors Buck Output Function (TC1303A)
- Monitors LDO Output Function (TC1303B)
- Monitors Both Buck and LDO Output
Functions (TC1303C and TC1304)
- 300 ms Delay Used for Processor Reset
• Sequenced Startup and Shutdown (TC1304)
• Small 10-pin 3x3 DFN or MSOP Package Options
• Operating Junction Temperature Range:
- -40°C to +125°C
• Undervoltage Lockout (UVLO)
• Output Short Circuit Protection
• Overtemperature Protection
Applications
• Cellular Phones
• Portable Computers
• USB-Powered Devices
• Handheld Medical Instruments
• Organizers and PDAs
Description
The TC1303/TC1304 combines a 500 mA
synchronous buck regulator and 300 mA Low-Dropout
Regulator (LDO) with a power-good monitor to provide
a highly integrated solution for devices that require
multiple supply voltages. The unique combination of an
integrated buck switching regulator and low-dropout
linear regulator provides the lowest system cost for
dual-output voltage applications that require one lower
processor core voltage and one higher bias voltage.
The 500 mA synchronous buck regulator switches at a
fixed frequency of 2.0 MHz when the load is heavy,
providing a low noise, small-size solution. When the
load on the buck output is reduced to light levels, it
changes operation to a Pulse Frequency Modulation
(PFM) mode to minimize quiescent current draw from
the battery. No intervention is necessary for smooth
transition from one mode to another.
The LDO provides a 300 mA auxiliary output that
requires a single 1 µF ceramic output capacitor,
minimizing board area and cost. The typical dropout
voltage for the LDO output is 137 mV for a 200 mA
load.
For the TC1303/TC1304, the power-good output is
based on the regulation of the buck regulator output, the
LDO output or the combination of both. The TC1304
features start-up and shutdown output sequencing.
The TC1303/TC1304 is available in either the 10-pin
DFN or MSOP package.
Additional protection features include: UVLO,
overtemperature and overcurrent protection on both
outputs.
For a complete listing of TC1303/TC1304 standard
parts, consult your Microchip representative.
500 mA Synchronous Buck Regulator,
+ 300 mA LDO with Power-Good Output
TC1303A/TC1303B/TC1303C/TC1304
DS21949C-page 2
© 2008 Microchip Technology Inc.
Package Types
10-Lead DFN
V
FB1
/V
OUT1
10-Lead MSOP
1
2
6
8
7
9
10
5
4
3
SHDN2
V
IN2
V
OUT2
A
GND
P
GND
LX
VIN1
SHDN1
V
FB1
/V
OUT1
PG
10-Lead DFN
10-Lead MSOP
1
2
6
8
7
9
10
5
4
3
SHDN
V
IN2
V
OUT2
A
GND
P
GND
L
X
V
IN1
V
FB1
/V
OUT1
PG
A
GND
TC1303A,B,C
TC1304
V
OUT2
V
IN2
PG
L
X
V
IN1
1
2
3
4
10
9
8
7 SHDN1
P
GND
SHDN2
EP
11
5
6
A
GND
V
FB1
/V
OUT1
V
OUT2
V
IN2
PG
L
X
V
IN1
1
2
3
4
10
9
8
7 A
GND
P
GND
SHDN
EP
11
5
6
A
GND
© 2008 Microchip Technology Inc.
DS21949C-page 3
TC1303A/TC1303B/TC1303C/TC1304
Functional Block Diagram – TC1303
Synchronous Buck Regulator
NDRV
PDRV
P
GND
V
IN1
L
X
Driver
P
GND
Control
V
OUT1
/V
FB1
V
IN2
SHDN1
PG
V
REF
LDO
V
OUT2
A
GND
A
GND
P
GND
Undervoltage Lockout
UVLO
UVLO
SHDN2
V
REF
TC1303A
(1)
,B
(2)
,C
(1)
options
PG Generator with Delay
(UVLO)
Sense LDO for B,C
Sense Switcher for A,C
Note 1: PG open-drain for A,C options
2: PG push-pull output for B option
TC1303A/TC1303B/TC1303C/TC1304
DS21949C-page 4
© 2008 Microchip Technology Inc.
Functional Block Diagram – TC1304
Synchronous Buck Regulator
NDRV
PDRV
P
GND
V
IN1
L
X
Driver
P
GND
Control
V
OUT1
/V
FB1
V
IN2
SHDN
PG
V
REF
LDO
V
OUT2
A
GND
A
GND
P
GND
Undervoltage Lockout
UVLO
UVLO
V
REF
TC1304
(Note)
PG Generator with Delay
(UVLO)
Output Voltage
Sequencer ckt.
A
GND
Note:
PG open-drain for TC1304
© 2008 Microchip Technology Inc.
DS21949C-page 5
TC1303A/TC1303B/TC1303C/TC1304
Typical Application Circuits
10-Lead DFN
1
2
6
8
7
9
10
5
4
3
SHDN2
V
IN2
V
OUT2
A
GND
P
GND
L
X
V
IN1
SHDN1
V
OUT1
PG
4.7 μF
Processor
RESET
Input
Voltage
4.7 μH
4.7
Μ
F
2.1V @
1
Μ
F
3.3V @
4.5V to 5.5V
Adjustable-Output Application
121 kΩ
200 kΩ
4.99 kΩ
33 pF
1
2
6
8
7
9
10
5
4
3
SHDN2
V
IN2
V
OUT2
A
GND
P
GND
L
X
V
IN1
SHDN1
V
OUT1
PG
4.7 μF
Processor
RESET
4.7 μH
4.7 μF
1.5V @ 500 mA
1 μF
2.5V @ 300 mA
2.7V to 4.2V
TC1303B
V
OUT1
V
OUT2
V
IN
V
OUT1
V
OUT2
1.0 μF
*Optional
Capacitor
V
IN2
300 mA
500 mA
Note: Connect DFN package exposed pad to A
GND
.
10-Lead MSOP
Fixed-Output Application
TC1303A
(Note)
R
PULLUP
1
2
6
8
7
9
10
5
4
3
SHDN
V
IN2
V
OUT2
A
GND
P
GND
L
X
V
IN1
V
OUT1
PG
4.7 μF
Processor
RESET
4.7 μH
4.7
Μ
F
1.2V @ 500 mA
1 μF
2.5V @ 300 mA
2.7V to 4.2V
V
OUT1
V
OUT2
V
IN
10-Lead MSOP
Fixed-Output Application
TC1304
R
PULLUP
A
GND
EP
11
TC1303A/TC1303B/TC1303C/TC1304
DS21949C-page 6
© 2008 Microchip Technology Inc.
NOTES:
© 2008 Microchip Technology Inc.
DS21949C-page 7
TC1303A/TC1303B/TC1303C/TC1304
1.0
ELECTRICAL
CHARACTERISTICS
Absolute Maximum Ratings †
V
IN
- A
GND
.......................................................................6.0V
All Other I/O ...............................(A
GND
- 0.3V) to (V
IN
+ 0.3V)
L
X
to P
GND
...............................................-0.3V to (V
IN
+ 0.3V)
P
GND
to A
GND
.................................................. -0.3V to +0.3V
Output Short Circuit Current ................................ Continuous
Power Dissipation (Note 7) .......................... Internally Limited
Storage temperature .....................................-65°C to +150°C
Ambient Temp. with Power Applied ................-40°C to +85°C
Operating Junction Temperature...................-40°C to +125°C
ESD protection on all pins (HBM)
....................................... 3 kV
† Notice: Stresses above those listed under “Maximum
Ratings” may cause permanent damage to the device. This is
a stress rating only and functional operation of the device at
those or any other conditions above those indicated in the
operational listings of this specification is not implied.
Exposure to maximum rating conditions for extended periods
may affect device reliability.
DC CHARACTERISTICS
Electrical Characteristics: V
IN1
=V
IN2
= SHDN1,2 = 3.6V, C
OUT1
= C
IN
= 4.7 µF, C
OUT2
= 1 µF, 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
Input/Output Characteristics
Input Voltage
V
IN
2.7
—
5.5
V
Note 1, Note 2, Note 8
Maximum Output Current
I
OUT1_MAX
500
—
—
mA
Note 1
Maximum Output Current
I
OUT2_MAX
300
—
—
mA
Note 1
Shutdown Current
Combined V
IN1
and V
IN2
Current
I
IN_SHDN
—
0.05
1
µA
SHDN1 = SHDN2 = GND
TC1303A,B Operating I
Q
TC1303C, TC1304 Operating I
Q
I
Q
I
Q
—
65.0
70.1
110
110
µA
SHDN1 = SHDN2 = V
IN2
I
OUT1
= 0 mA, I
OUT2
= 0 mA
Synchronous Buck I
Q
—
38
—
µA
SHDN1 = V
IN
, SHDN2 = GND
LDO I
Q
—
46
—
µA
SHDN1 = GND, SHDN2 = V
IN2
Shutdown/UVLO/Thermal Shutdown Characteristics
SHDN1,SHDN2, SHDN (TC1304)
Logic Input Voltage Low
V
IL
—
—
15
%V
IN
V
IN1
=V
IN2
= 2.7V to 5.5V
SHDN1,SHDN2, SHDN (TC1304)
Logic Input Voltage High
V
IH
45
—
—
%V
IN
V
IN1
=V
IN2
= 2.7V to 5.5V
SHDN1,SHDN2, SHDN (TC1304)
Input Leakage Current
I
IN
-1.0
±0.01
1.0
µA
V
IN1
=V
IN2
= 2.7V to 5.5V
SHDNX = GND
SHDNY = V
IN
Thermal Shutdown
T
SHD
—
165
—
°C
Note 6, Note 7
Thermal Shutdown Hysteresis
T
SHD-HYS
—
10
—
°C
Undervoltage Lockout
(V
OUT1
and V
OUT2
)
UVLO
2.4
2.55
2.7
V
V
IN1
Falling
Undervoltage Lockout Hysteresis
UVLO
-
HYS
—
200
—
mV
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.
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
—
ms
T
R
= 10% to 90%
R
DSon
P-Channel
R
DSon-P
—
450
—
m
Ω
I
P
=100 mA
R
DSon
N-Channel
R
DSon-N
—
450
—
m
Ω
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
= 50 mA,
SHDN1 = GND
DC CHARACTERISTICS (CONTINUED)
Electrical Characteristics: V
IN1
=V
IN2
= SHDN1,2 = 3.6V, C
OUT1
= C
IN
= 4.7 µF, C
OUT2
= 1 µF, 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.
© 2008 Microchip Technology Inc.
DS21949C-page 9
TC1303A/TC1303B/TC1303C/TC1304
Output Short Circuit Current
(Average)
I
OUTsc2
—
240
—
mA
R
LOAD2
≤ 1Ω
Wake-Up Time (From SHDN2
mode), (V
OUT2
)
t
WK
—
31
100
µs
I
OUT1
= I
OUT2
= 50 mA
Settling Time (From SHDN2
mode), (V
OUT2
)
t
S
—
100
—
µs
I
OUT1
= I
OUT2
= 50 mA
Power-Good (PG)
Voltage Range PG
V
PG
1.0
1.2
—
5.5
5.5
V
T
A
= 0°C to +70°C
T
A
= -40°C to +85°C
V
IN
≤ 2.7 I
SINK
= 100 µA
PG Threshold High
(V
OUT1
or V
OUT2
)
V
TH_H
—
94
96
% of
V
OUTX
On Rising V
OUT1
or V
OUT2
V
OUTX
= V
OUT1
or V
OUT2
PG Threshold Low
(V
OUT1
or V
OUT2
)
V
TH_L
89
92
—
% of
V
OUTX
On Falling V
OUT1
or V
OUT2
V
OUTX
= V
OUT1
or V
OUT2
PG Threshold Hysteresis
(V
OUT1
and V
OUT2
)
V
TH_HYS
—
2
—
% of
V
OUTX
V
OUTX
= V
OUT1
or V
OUT2
PG Threshold Tempco
ΔV
TH
/
ΔT
—
30
—
ppm/°C
PG Delay
t
RPD
—
165
—
µs
V
OUT1
or V
OUT2
= (V
TH
+ 100 mV)
to (V
TH
- 100 mV)
PG Active Time-out Period
t
RPU
140
262
560
ms
V
OUT1
or V
OUT2
= V
TH
- 100 mV
to V
TH +
100 mV,
I
SINK
= 1.2 mA
PG Output Voltage Low
PG_V
OL
—
—
0.2
V
V
OUT1
or V
OUT2
= V
TH
- 100 mV
,
I
PG
= 1.2 mA V
IN2
> 2.7V
I
PG
= 100 µA, 1.0V < V
IN2
< 2.7V
PG Output Voltage High
(TC1303B only)
PG_V
OH
0.9* V
OUT2
—
—
V
V
OUT1
or V
OUT2
= V
TH
+ 100 mV
V
OUT2
≥ 1.8V, I
PG
= - 500 µA
V
OUT2
< 1.8V,I
PG
= - 300 µA
DC CHARACTERISTICS (CONTINUED)
Electrical Characteristics: V
IN1
=V
IN2
= SHDN1,2 = 3.6V, C
OUT1
= C
IN
= 4.7 µF, C
OUT2
= 1 µF, 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.
TC1303A/TC1303B/TC1303C/TC1304
DS21949C-page 10
© 2008 Microchip Technology Inc.
TEMPERATURE SPECIFICATIONS
Electrical Specifications: Unless otherwise indicated, all limits are specified for: V
IN
= +2.7V to +5.5V
Parameters
Sym
Min
Typ
Max
Units
Conditions
Temperature Ranges
Operating Junction Temperature
Range
T
J
-40
—
+125
°C
Steady state
Storage Temperature Range
T
A
-65
—
+150
°C
Maximum Junction Temperature
T
J
—
—
+150
°C
Transient
Thermal Package Resistances
Thermal Resistance, 10L-DFN
θ
JA
—
41
—
°C/W Typical 4-layer Board with
Internal Ground Plane and 2 Vias
in Thermal Pad
Thermal Resistance, 10L-MSOP
θ
JA
—
113
—
°C/W Typical 4-layer Board with
Internal Ground Plane