TPS61202 [TI]
LOW INPUT VOLTAGE SYNCHRONOUS BOOST CONVERTER WITH 1.3-A SWITCHES; 1.3 - C开关低输入电压同步升压转换器
| 型号： | TPS61202 |
| 厂家： | 
TEXAS INSTRUMENTS |
| 描述： | LOW INPUT VOLTAGE SYNCHRONOUS BOOST CONVERTER WITH 1.3-A SWITCHES |
| 文件： | 总26页 (文件大小：828K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
TPS61200
TPS61201
(3,25 mm x 3,25 mm)
TPS61202
www.ti.com
SLVS577A–MARCH 2007–REVISED JUNE 2007
LOW INPUT VOLTAGE SYNCHRONOUS BOOST CONVERTER
WITH 1.3-A SWITCHES
FEATURES
•
Power Save Mode for Improved Efficiency at
Low Output Power
•
More than 90% Efficiency at
•
•
•
•
Forced fixed Frequency Operation possible
Load Disconnect During Shutdown
Overtemperature Protection
–
300 mA Output Current at 3.3 V
(VIN ≥ 2.4 V)
–
600 mA Output Current at 5 V (VIN ≥ 3 V)
•
Automatic Transition between Boost Mode
and Down Conversion Mode
Small 3 mm x 3 mm QFN-10 Package
APPLICATIONS
•
•
•
Device Quiescent Current less than 55 μA
•
All Single-Cell, Two-Cell and Three-Cell
Alkaline, NiCd or NiMH or Single-Cell Li
Battery Powered Products
Startup into Full Load at 0.5 V Input Voltage
Operating Input Voltage Range from
0.3 V to 5.5 V
•
•
•
•
•
•
Fuel Cell And Solar Cell Powered Products
Portable Audio Players
PDAs
Cellular Phones
Personal Medical Products
White LED's
•
•
•
Programmable Undervoltage Lockout
Threshold
Output Short Circuit Protection Under all
Operating Conditions
Fixed and Adjustable Output Voltage Options
from 1.8 V to 5.5 V
DESCRIPTION
The TPS6120x devices provide a power supply solution for products powered by either a single-cell, two-cell, or
three-cell alkaline, NiCd or NiMH, or one-cell Li-Ion or Li-polymer battery. It is also used in fuel cell or solar cell
powered devices where the capability of handling low input voltages is essential. Possible output currents are
depending on the input to output voltage ratio. The devices provides output currents up to 600 mA at a 5-V
output while using a single-cell Li-Ion or Li-Polymer battery, and discharge it down to 2.5 V. The boost converter
is based on a fixed frequency, pulse-width-modulation (PWM) controller using synchronous rectification to obtain
maximum efficiency. At low load currents, the converter enters the Power Save mode to maintain a high
efficiency over a wide load current range. The Power Save mode can be disabled, forcing the converter to
operate at a fixed switching frequency. The maximum average input current is limited to a value of 1500 mA.
The output voltage can be programmed by an external resistor divider, or is fixed internally on the chip. The
converter can be disabled to minimize battery drain. During shutdown, the load is completely disconnected from
the battery. The device is packaged in a 10-pin QFN PowerPAD™ package (DRC) measuring 3 mm x 3 mm.
L1
2.2 mH
VIN
L
VOUT
VAUX
C1
VIN
0.3 V to 5.5 V
EN
C2
10 mF
VOUT
1.8 V to 5.5 V
R
R
1
PS
C3
10 mF
0.1 mF
UVLO
FB
2
GND
PGND
TPS61200
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas
Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
PowerPAD is a trademark of Texas Instruments.
PRODUCTION DATA information is current as of publication date.
Copyright © 2007, Texas Instruments Incorporated
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
TPS61200
TPS61201
TPS61202
www.ti.com
SLVS577A–MARCH 2007–REVISED JUNE 2007
These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam
during storage or handling to prevent electrostatic damage to the MOS gates.
AVAILABLE DEVICE OPTIONS(1)
OUTPUT VOLTAGE
DC/DC
PACKAGE
MARKING
TA
PACKAGE(2)
PART NUMBER(3)
Adjustable
3.3 V
BRR
BRS
BRT
TPS61200DRC
TPS61201DRC
TPS61202DRC
–40°C to 85°C
10-Pin QFN
5 V
(1) Contact the factory to check availability of other fixed output voltage versions.
(2) For the most current package and ordering information, see the Package Option Addendum at the end of this document, or see the TI
website at www.ti.com.
(3) The DRC package is available taped and reeled. Add R suffix to device type (e.g., TPS61200DRCR) to order quantities of 3000 devices
per reel. It is also available in minireels. Add a T suffix to the device type (i.e. TPS61200DRCT) to order quantities of 250 devices per
reel.
ABSOLUTE MAXIMUM RATINGS
over operating free-air temperature range (unless otherwise noted)(1)
TPS6120x
– 0.3 to 7
–40 to 150
–65 to 150
4
UNIT
V
VI
Input voltage range on VIN, L, VAUX, VOUT, PS, EN, FB, UVLO
Operating junction temperature range
TJ
°C
°C
kV
V
Tstg
Storage temperature range
(2)
Human Body Model (HBM)
(2)
ESD
Machine Model (MM)
200
Charged Device Model (CDM)(2)
1.5
kV
(1) Stresses beyond those listed under "absolute maximum ratings" may cause permanent damage to the device. These are stress ratings
only, and functional operation of the device at these or any other conditions beyond those indicated under "recommended operating
conditions" is not implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
(2) ESD testing is performed according to the respective JESD22 JEDEC standard.
DISSIPATION RATINGS TABLE
THERMAL RESISTANCE
POWER RATING
A ≤ 25°C
DERATING FACTOR ABOVE
PACKAGE
ΘJA
T
TA = 25°C
DRC
48.7 °C/W
2054 mW
21 mW/°C
RECOMMENDED OPERATING CONDITIONS
MIN
0.3
NOM
MAX
5.5
UNIT
V
VSS
TA
Supply voltage at VIN
Operating free air temperature range
Operating virtual junction temperature range
–40
–40
85
°C
TJ
125
°C
2
Submit Documentation Feedback
TPS61200
TPS61201
TPS61202
www.ti.com
SLVS577A–MARCH 2007–REVISED JUNE 2007
ELECTRICAL CHARACTERISTICS
over recommended free-air temperature range and over recommended input voltage range (typical at an ambient
temperature range of 25°C) (unless otherwise noted)
DC/DC STAGE
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
5.5
UNIT
V
VI
Input voltage range
0.3
VI
Minimum input voltage at startup
TPS61200 output voltage range
TPS61200 feedback voltage
TPS61201 output voltage
TPS61202 output voltage
Oscillator frequency
0.5
V
VO
VFB
VOUT
VOUT
f
1.8
495
5.5
V
500
3.3
5.0
505
3.33
5.05
1650
1500
mV
V
VIN < VOUT, PS = 1
3.27
4.95
1250
1200
VIN < VOUT, PS = 1
V
kHz
mA
mΩ
mΩ
ISW
average switch current limit
Rectifying switch on resistance
Main switch on resistance
Line regulation
VOUT = 3.3 V
1350
180
150
0.1%
0.1%
1
VOUT = 3.3 V
VOUT = 3.3 V
VIN < VOUT, PS = 1
VIN < VOUT, PS = 1
0.5%
0.5%
2
Load regulation
VIN
μA
μA
μA
μA
μA
μA
IO = 0 mA, VEN = VIN = 1.2 V,
VOUT = 3.3 V, VAUX = 3.3 V
PS = 0
Quiescent current
VOUT
VAUX
VIN
50
70
6
4
0.5
1
1.5
2
Shutdown current
VEN = 0 V, VIN = 1.2 V
VAUX
Leakage current into L
VEN = 0 V, VIN = 1.2 V, VL = 1.2 V
0.01
1
CONTROL STAGE
PARAMETER
Auxiliary Output Voltage
TEST CONDITIONS
MIN
TYP
MAX
5.5
UNIT
V
VAUX
VIL
2.4
0.9 × VIN
0.8 × VIN
1.2
EN input low voltage
EN input high voltage
EN input low voltage
EN input high voltage
EN input low voltage
EN input high voltage
PS input low voltage
PS input high voltage
EN, PS input current
VIN < 0.8 V
0.1 × VIN
V
VIH
VIL
VIN < 0.8 V
V
0.8 V ≤ VIN ≤ 1.5 V
0.8 V ≤ VIN ≤ 1.5 V
VIN > 1.5 V
0.2 × VIN
0.4
V
VIH
VIL
V
V
VIH
VIL
VIN > 1.5 V
V
0.4
V
VIH
1.2
V
Clamped on GND or VIN (VIN < 1.5 V)
0.01
250
0.1
μA
mV
VUVLO
VUVLO
Undervoltage lockout threshold for VUVLO decreasing
turn off
235
330
265
Undervoltage lockout threshold for VUVLO increasing
turn on
350
370
mV
UVLO input current
VUVLO = 0.5 V
0.3
7
μA
V
Overvoltage protection threshold
Overtemperature protection
Overtemperature hysteresis
5.5
140
20
°C
°C
3
Submit Documentation Feedback
TPS61200
TPS61201
TPS61202
www.ti.com
SLVS577A–MARCH 2007–REVISED JUNE 2007
PIN ASSIGNMENTS
DRC PACKAGE
(TOP VIEW)
VAUX
FB
GND
VOUT
L
PS
PGND
VIN
UVLO
EN
Terminal Functions
TERMINAL
I/O
DESCRIPTION
NAME
EN
NO.
6
I
I
Enable input (1: enabled, 0: disabled).
FB
10
9
Voltage feedback of adjustable versions, must be connected to VOUT at fixed output voltage versions
Control / logic ground
GND
PS
8
I
I
I
Enable/disable Power Save mode (1 : disabled, 0: enabled)
Connection for Inductor
L
3
UVLO
PGND
VIN
7
Undervoltage lockout comparator input, must be connected to VAUX if not used
Power ground
4
5
I
Boost converter input voltage
VOUT
VAUX
PowerPAD™
2
O
Boost converter output
1
O/I
Supply voltage for control stage
Must be soldered to achieve appropriate power dissipation. Should be connected to PGND.
4
Submit Documentation Feedback
TPS61200
TPS61201
TPS61202
www.ti.com
SLVS577A–MARCH 2007–REVISED JUNE 2007
FUNCTIONAL BLOCK DIAGRAM (TPS61200)
L
VOUT
VCC
Control
Current
Sensor
VAUX
VOUT
PGND
VIN
Gate
Control
VCC
Modulator
Oscillator
FB
VREF
PS
Device
Control
EN
UVLO
Temperature
Control
PGND
GND
PGND
PARAMETER MEASUREMENT INFORMATION
L1
VIN
VIN
L
VOUT
C1
VOUT
VAUX
EN
R1
R2
C2
PS
C3
UVLO
FB
GND
PGND
TPS61200
List of Components:
COMPONENT REFERENCE
PART NUMBER
MANUFACTURER
VALUE
C1
C2
L1
any
10 μF, X7R Ceramic
2 x 10 μF, X7R Ceramic
2.2 μH
any
LPS3015-222ML
Coilcraft
5
Submit Documentation Feedback
TPS61200
TPS61201
TPS61202
www.ti.com
SLVS577A–MARCH 2007–REVISED JUNE 2007
TYPICAL CHARACTERISTICS
Table of Graphs
FIGURE
Maximum output current
vs Input voltage
1
2
vs Output current (TPS61200), Power Save Enabled
vs Output current (TPS61200), Power Save Disabled
vs Output current (TPS61201), Power Save Enabled
vs Output current (TPS61201), Power Save Disabled
vs Output current (TPS61202), Power Save Enabled
vs Output current (TPS61202), Power Save Disabled
vs Input voltage (TPS61201), Power Save Enabled
vs Input voltage (TPS61201), Power Save Disabled
vs Input voltage (TPS61202), Power Save Enabled
vs Input voltage (TPS61202), Power Save Disabled
vs Output current (TPS61201)
3
4
5
6
Efficiency
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
Output voltage
vs Output current (TPS61202)
Output Voltage TPS61201, Power Save Mode Disabled
Output Voltage TPS61202, Power Save Mode Disabled
Output Voltage TPS61201, Power Save Mode Enabled
Output Voltage TPS61202, Power Save Mode Enabled
TPS61201 Load Transient Response
Waveforms
TPS61202 Load Transient Response
TPS61201 Line Transient Response
TPS61202 Line Transient Response
TPS61201 Startup after Enable
TPS61202 Startup after Enable
MAXIMUM OUTPUT CURRENT
EFFICIENCY
vs
vs
INPUT VOLTAGE
OUTPUT CURRENT
2000
1800
100
90
TPS61200
= 1.8 V,
V
O
Power Save
Enabled
TPS61200,
= 1.8 V
1600
1400
1200
1000
800
80
V
O
V = 1.8 V
70
60
50
I
TPS61201,
= 3.3 V
V
O
TPS61202,
= 5 V
V = 0.9 V
I
40
30
20
V
O
600
400
200
0
10
0
0.10
1
10 100
- Output Current - mA
1 k
10 k
0.2 0.6
1 1.4 1.8 2.2 2.6 3 3.4 3.8 4.2 4.6 5 5.4
I
O
V - Input Voltage - V
I
Figure 1.
Figure 2.
6
Submit Documentation Feedback
TPS61200
TPS61201
TPS61202
www.ti.com
SLVS577A–MARCH 2007–REVISED JUNE 2007
EFFICIENCY
vs
OUTPUT CURRENT
EFFICIENCY
vs
OUTPUT CURRENT
100
90
100
TPS61201
= 3.3 V,
TPS61200
= 1.8 V,
V = 2.4 V
I
V = 1.8 V
I
V
V
O
Power Save Enabled
90
80
O
Power Save Disabled
80
70
60
50
70
60
50
V = 1.8 V
I
V = 0.9 V
I
V = 0.9 V
I
40
30
20
40
30
20
10
0
10
0
0.10
1
10 100
- Output Current - mA
1 k
10 k
0.10
1
10 100
- Output Current - mA
1 k
10 k
I
I
O
O
Figure 3.
Figure 4.
EFFICIENCY
vs
OUTPUT CURRENT
EFFICIENCY
vs
OUTPUT CURRENT
100
90
100
90
V = 2.4 V
I
V = 3.6 V
TPS61201
= 3.3 V,
I
V
V = 2.4 V
O
Power Save Disabled
I
80
80
70
60
50
70
60
50
V = 1.8 V
I
V = 1.8 V
I
V = 0.9 V
I
V = 0.9 V
I
40
30
20
40
30
20
TPS61202
= 5 V,
V
O
Power Save Enabled
10
0
10
0
0.10
1
10 100
- Output Current - mA
1 k
10 k
0.10
1
10
I - Output Current - mA
O
100
1 k
10 k
I
O
Figure 5.
Figure 6.
7
Submit Documentation Feedback
TPS61200
TPS61201
TPS61202
www.ti.com
SLVS577A–MARCH 2007–REVISED JUNE 2007
EFFICIENCY
vs
OUTPUT CURRENT
EFFICIENCY
vs
INPUT VOLTAGE
100
100
90
V = 3.6 V
V = 2.4 V
I
I
= 500 mA
I = 1000 mA
O
I
O
90
I
= 100 mA
O
80
70
60
50
80
70
60
50
40
V = 1.8 V
I
I
= 10 mA
O
V = 0.9 V
I
40
30
20
30
20
TPS61202
= 5 V,
TPS61201
= 3.3 V,
V
V
O
Power Save Disabled
O
Power Save Enabled
10
0
10
0
0.10
1
10 100
- Output Current - mA
1 k
10 k
0
0.5
1
1.5
2
2.5
3
3.5 4 4.5 5 5.5
I
V - Input Voltage - V
I
O
Figure 7.
Figure 8.
EFFICIENCY
vs
INPUT VOLTAGE
EFFICIENCY
vs
INPUT VOLTAGE
100
90
100
90
I
= 500 mA
I
= 500 mA
I
= 1000 mA
O
O
O
I
= 100 mA
O
80
70
80
70
I
= 1000 mA
O
60
50
40
60
50
40
I
= 100 mA
= 10 mA
O
I
= 10 mA
O
I
O
30
20
30
20
TPS61201
= 3.3 V,
TPS61202
V = 5 V,
O
V
O
Power Save Disabled
10
0
10
0
Power Save Enabled
0
0.5
1
1.5
2
2.5
3
3.5 4 4.5 5 5.5
0
0.5
1
1.5
2
2.5
3
3.5 4 4.5
5
5.5
V - Input Voltage - V
I
V - Input Voltage - V
I
Figure 9.
Figure 10.
8
Submit Documentation Feedback
TPS61200
TPS61201
TPS61202
www.ti.com
SLVS577A–MARCH 2007–REVISED JUNE 2007
EFFICIENCY
vs
INPUT VOLTAGE
OUTPUT VOLTAGE
vs
OUTPUT CURRENT
100
90
3.33
I
= 500 mA
O
V = 2.4 V
I
80
70
I
= 1000 mA
O
I
= 100 mA
O
60
50
40
3.30
I
= 10 mA
O
30
20
TPS61202
= 5 V,
TPS61201
= 3.3 V,
V
V
O
Power Save Disabled
O
Power Save Disabled
10
0
3.27
0
0.5
1
1.5
2
2.5
3
3.5 4 4.5
5
5.5
1
10
100
1000
V - Input Voltage - V
I
I
- Output Current - mA
O
Figure 11.
Figure 12.
OUTPUT VOLTAGE
vs
OUTPUT CURRENT
OUTPUT VOLTAGE, POWER SAVE MODE DISABLED
5.05
TPS61201
= 3.3 V,
TPS61202
= 5 V,
V = 1.8 V, R = 11W
I
L
V
V
O
Power Save Disabled
O
Power Save Disabled
V = 2.4 V
I
5
4.95
1
10
100
- Output Current - mA
100
t - Time - 0.5 ms/div
I
O
Figure 13.
Figure 14.
9
Submit Documentation Feedback
TPS61200
TPS61201
TPS61202
www.ti.com
SLVS577A–MARCH 2007–REVISED JUNE 2007
OUTPUT VOLTAGE, POWER SAVE MODE DISABLED
OUTPUT VOLTAGE IN POWER SAVE MODE
V = 1.8 V, R = 33 kW
TPS61202
= 5 V,
V = 1.8 V, R = 17W
I
L
I
L
V
O
Power Save Disabled
TPS61201
= 3.3 V,
V
O
Power Save Enabled
t - Time - 1 ms/div
t - Time - 2 ms/div
Figure 15.
Figure 16.
OUTPUT VOLTAGE IN POWER SAVE MODE
TPS61202
LOAD TRANSIENT RESPONSE
V = 1.8 V, R = 55 kW
TPS61201
= 3.3 V
V = 1.8 V, I = 300 mA to 400 mA
I L
I
L
V
= 5 V,
V
O
Power Save Enabled
O
t - Time - 100 ms/div
t - Time - 1 ms/div
Figure 17.
Figure 18.
10
Submit Documentation Feedback
TPS61200
TPS61201
TPS61202
www.ti.com
SLVS577A–MARCH 2007–REVISED JUNE 2007
LOAD TRANSIENT RESPONSE
LINE TRANSIENT RESPONSE
V = 1.8 V, I = 150 mA to 250 mA
V = 1.8 V to 2.4 V, R = 11W
I
L
I
L
TPS61202
= 5 V
V
O
TPS61201
= 3.3 V
V
O
t - Time - 1 ms/div
t - Time - 2 ms/div
Figure 19.
Figure 20.
LINE TRANSIENT RESPONSE
START-UP AFTER ENABLE
V = 3 V to 3.6 V, R = 17W
I
L
Enable 5 V/div, DC
Voltage at VAUX 2 V/div, DC
Output Voltage 2 V/div, DC
Voltage at L 2 V/div, DC
Inductor Current 500 mA/div, DC
TPS61202
= 5 V
V
TPS61201
= 3.3 V
O
V = 1.8 V, R = 11W
I
L
V
O
t - Time - 2 ms/div
t - Time - 100 ms/div
Figure 21.
Figure 22.
11
Submit Documentation Feedback
TPS61200
TPS61201
TPS61202
www.ti.com
SLVS577A–MARCH 2007–REVISED JUNE 2007
START-UP AFTER ENABLE
Enable 5 V/div, DC
Voltage at VAUX 2 V/div, DC
Output Voltage 2 V/div, DC
Voltage at L 2 V/div, DC
Inductor Current 500 mA/div, DC
TPS61201
= 3.3 V
V = 1.8 V, R = 17W
I
L
V
O
t - Time - 100 ms/div
Figure 23.
12
Submit Documentation Feedback
TPS61200
TPS61201
TPS61202
www.ti.com
SLVS577A–MARCH 2007–REVISED JUNE 2007
DETAILED DESCRIPTION
CONTROLLER CIRCUIT
The controlling circuit of the device is based on an average current mode topology. The average inductor current
is regulated by a fast current regulator loop which is controlled by a voltage control loop. The controller also
uses input and output voltage feedforward. Changes of input and output voltage are monitored and can
immediately change the duty cycle in the modulator to achieve a fast response to those errors. The voltage error
amplifier gets its feedback input from the FB pin. For adjustable output voltages, a resistive voltage divider must
be connected to that pin. For fixed output voltages, FB must be connected to the output voltage to directly sense
the voltage. Fixed output voltage versions use a trimmed internal resistive divider. The feedback voltage is
compared with the internal reference voltage to generate a stable and accurate output voltage.
The controller circuit also senses the average input current as well as the peak input current. Thus, the
maximum input power is controlled as well as the maximum peak current to achieve a safe and stable operation
under all possible conditions. To protect the device from overheating, an internal temperature sensor is
implemented.
Synchronous Operation
The device uses three internal N-channel MOSFETs to maintain synchronous power conversion at all possible
operating conditions. This enables the device to keep high efficiency over a wide input voltage and output power
range.
To avoid ground shift problems due to the high currents in the switches, two separate ground pins GND and
PGND are used. The reference for all control functions is the GND pin. The power switches are connected to
PGND. Both grounds must be connected on the PCB at only one point ideally close to the GND pin. Due to the
3-switch topology, the load is always disconnected from the input during shutdown of the converter.
Down Regulation
A boost converter only regulates output voltages which are higher than the input voltage. This device operates
differently. For example, it is able to regulate 3 V at the output with two fresh alkaline cells at the input having a
total cell voltage of 3.2 V. Another example is powering white LEDs with a forward voltage of 3.6 V from a fully
charged Li-Ion cell with an output voltage of 4.2 V. To control these applications properly, a Down Conversion
mode is implemented.
If the input voltage reaches or exceeds the output voltage, the converter automatically changes to a Down
Conversion mode. In this mode, the control circuit changes the behavior of the two rectifying switches. While
continuing switching it sets the voltage drop across the rectifying switches as high as needed to regulate the
output voltage. This means the power losses in the converter increase. This must be taken into account for
thermal consideration.
Power Save Mode
The Power Save (PS) pin can be used to select different operation modes. To enable Power Save mode the PS
pin must be set low. Power Save mode is used to improve efficiency at light load. If Power Save mode is
enabled, the converter stops operating if the average inductor current decreases below about 300 mA and the
output voltage is at or above its nominal value. If the output voltage decreases below its nominal value, the
device ramps up the output voltage again by starting operation using a programmed average inductor current
higher than required by the current load condition. Operation can last for one or several pulses. The converter
stops operating once the conditions for stopping operation are met again.
The Power Save mode can be disabled by programming high at the PS pin. In Down Conversion mode, Power
Save mode is always enabled and the device cannot be forced into fixed frequency operation at light loads. The
PS input supports standard logic thresholds.
13
Submit Documentation Feedback
TPS61200
TPS61201
TPS61202
www.ti.com
SLVS577A–MARCH 2007–REVISED JUNE 2007
DETAILED DESCRIPTION (continued)
Device Enable
The device is put into operation when EN is set high. It is put into a Shutdown mode when EN is set to GND. In
Shutdown mode, the regulator stops switching, all internal control circuitry including the low-battery comparator
is switched off, and the load is disconnected from the input. This also means that the output voltage can drop
below the input voltage during shutdown. During start-up of the converter, the duty cycle and the peak current
are limited in order to avoid high peak currents drawn from the battery.
Softstart and Short-Circuit Protection
After being enabled, the device starts operating. At first it keeps the main output VOUT disconnected, and
charges the capacitor at VAUX. If the capacitor at VAUX is charged to about 2.5 V, the device switches to
normal operation. This means VOUT is turned on and the capacitor at VOUT is charged while the load
connected to the device is supplied. To ramp up the output voltage in a controlled way, the average current limit
is set to 400 mA and rise proportional to the increase of the output voltage. At an output voltage of about 1.2 V,
the current limit is at its nominal value. If the output voltage does not increase, the current limit will not increase.
There is no timer implemented. Thus the output voltage overshoot at startup, as well as the inrush current, is
kept at a minimum. The device ramps up the output voltage in a controlled manner even if a large capacitor is
connected at the output. When the output voltage does not increase above 1.2 V, the device assumes a
short-circuit at the output, and keeps the current limit low to protect itself and the application. When there is a
short at the output during operation, the current limit is decreased accordingly.
Undervoltage Lockout
An undervoltage lockout function prevents the main output at VOUT from being supplied if the voltage at UVLO
drops below 0.25 V. When using a resistive divider at the voltage to be monitored, for example the supply
voltage, any threshold for the monitored voltage can be programmed. If in undervoltage lockout mode, the
device still maintains its supply voltage at VAUX, but it is not turned off until EN is programmed low. This
undervoltage lockout function is implemented in order to prevent the malfunctioning of the converter.
Overtemperature Protection
The device has a built-in temperature sensor which monitors the internal IC temperature. If the temperature
exceeds the programmed threshold (see electrical characteristics table), the device stops operating. As soon as
the IC temperature has decreased below the programmed threshold, it starts operating again. There is a built-in
hysteresis to avoid unstable operation at IC temperatures at the overtemperature threshold.
14
Submit Documentation Feedback
TPS61200
TPS61201
TPS61202
www.ti.com
SLVS577A–MARCH 2007–REVISED JUNE 2007
APPLICATION INFORMATION
DESIGN PROCEDURE
The TPS6120x DC/DC converters are intended for systems powered by a single up to triple cell Alkaline, NiCd,
NiMH battery with a typical terminal voltage between 0.7 V and 5.5 V. They can also be used in systems
powered by one-cell Li-Ion or Li-Polymer with a typical voltage between 2.5 V and 4.2 V. Additionally, any other
voltage source like solar cells or fuel cells with a typical output voltage between 0.3 V and 5.5 V can power
systems where the TPS6120x is used.
Programming the Output Voltage
Within the TPS6120X family, there are fixed and adjustable output voltage versions available. To properly
configure the fixed output voltage devices, the FB pin is used to sense the output voltage. This means that it
must be connected directly to VOUT. At the adjustable output voltage versions, an external resistor divider is
used to adjust the output voltage. The resistor divider must be connected between VOUT, FB and GND. When
the output voltage is regulated properly, the typical value of the voltage at the FB pin is 500 mV. The maximum
recommended value for the output voltage is 5.5 V. The current through the resistive divider should be about
100 times greater than the current into the FB pin. The typical current into the FB pin is 0.01 μA, and the voltage
across the resistor between FB and GND, R2, is typically 500 mV. Based on those two values, the
recommended value for R2 should be lower than 500 kΩ, in order to set the divider current at 1 μA or higher. It
is recommended to keep the value for this resistor in the range of 200 kΩ. The value of the resistor connected
between VOUT and FB, R1, depending on the needed output voltage (VOUT), can be calculated using
Equation 1:
æ
ç
è
ö
V
OUT
R1 = R2 x
- 1
÷
V
FB
ø
(1)
If as an example, an output voltage of 3.3 V is needed, a 1-MΩ resistor should be chosen for R1 when for R2 a
180-kΩ has been selected.
L1
VIN
VIN
L
VOUT
VAUX
VOUT
C1
EN
R3
R4
R1
R2
C2
PS
C3
UVLO
FB
GND
PGND
TPS61200
Figure 24. Typical Application Circuit for Adjustable Output Voltage Option
Programming the UVLO Threshold Voltage
The UVLO input can be used to shut down the main output if the supply voltage is getting too low. The internal
reference threshold is typically 250 mV. If the supply voltage should cause the shutdown when it is dropping
below 250 mV, it can be connected directly to the UVLO pin. If the shutdown has already happen at higher
voltages, a resistor divider can be used. R3 and R4 in Figure 24 show an example of how to monitor the input
voltage of the circuit. The current through the resistive divider should be about 100 times greater than the
current into the UVLO pin. The typical current into the UVLO pin is 0.01 μA, and the voltage across R4 is equal
to the UVLO voltage threshold that is generated on-chip, which has a value of 250 mV. The recommended value
for R4 is; therefore, in the range of 250 kΩ. From this, the value of resistor R3, depending on the desired
shutdown voltage VINMIN, can be calculated using Equation 2.
15
Submit Documentation Feedback
TPS61200
TPS61201
TPS61202
www.ti.com
SLVS577A–MARCH 2007–REVISED JUNE 2007
æ
ö
V
INMIN
R3 = R4 x
- 1
ç
÷
ç
÷
V
UVLO
è
ø
(2)
Inductor Selection
To make sure that the TPS6120X devices can operate, an inductor must be connected between pin VIN and pin
L. To estimate the minimum inductance value Equation 3 can be used.
ms
L
= V x 0.5
IN
MIN
A
(3)
In this equation, f is the minimum switching frequency. In Equation 3, the minimum inductance, LMIN, for boost
mode operation is calculated. VIN is the maximum input voltage. The recommended inductor value range is
between 1.5 μH and 4.7 μH. The minimum inductor value should not be below 1.5 μH, even if Equation 3 yields
in something lower. Using 2.2 μH is recommended anyway for getting best performance over the whole input
and output voltage range.
With the chosen inductance value, the peak current for the inductor in steady state operation can be calculated.
Equation 4 shows how to calculate the peak current I.
V
x V
- V
IN
V
x I
OUT
(
)
IN
OUT
x f x L
OUT
OUT
0.8 x V
I
=
+
LMAX
2 x V
IN
(4)
This would be the critical value for the current rating for selecting the inductor. It also needs to be taken into
account that load transients and error conditions may cause higher inductor currents. The following inductor
series from different suppliers have been used with TPS6120x converters:
Table 1. List of Inductors
VENDOR
INDUCTOR SERIES
LPS3015
Coilcraft
LPS4012
Murata
LQH3NP
Tajo Yuden
Wurth Elektronik
NR3015
WE-TPC Typ S
Capacitor Selection
Input Capacitor
At least a 4.7 μF input capacitor is recommended to improve transient behavior of the regulator and EMI
behavior of the total power supply circuit. A ceramic capacitor placed as close as possible to the VIN and PGND
pins of the IC is recommended.
Output Capacitor
For the output capacitor, it is recommended to use small ceramic capacitors placed as close as possible to the
VOUT and PGND pins of the IC. If, for any reason, the application requires the use of large capacitors which
can not be placed close to the IC, using a smaller ceramic capacitor in parallel to the large one is recommended.
This small capacitor should be placed as close as possible to the VOUT and PGND pins of the IC.
To get an estimate of the recommended minimum output capacitance, Equation 5 can be used.
mF
C
= 5 x L x
OUT
mH
(5)
A capacitor with a value in the range of the calculated minimum should be used. This is required to maintain
control loop stability. There are no additional requirements regarding minimum ESR. There is also no upper limit
for the output capacitance value. Larger capacitors cause lower output voltage ripple as well as lower output
voltage drop during load transients.
16
Submit Documentation Feedback
TPS61200
TPS61201
TPS61202
www.ti.com
SLVS577A–MARCH 2007–REVISED JUNE 2007
Capacitor at VAUX
Between the VAUX pin and GND a capacitor must be connected. This capacitor is used to maintain and filter the
control supply voltage. It is charged during startup and before the main output VOUT is turned on. To ensure
stable operation, using at least 0.1μF is recommended. At output voltages below 2.5 V, the capacitance should
be in the range of 1 μF. Since this capacitor is also used as a snubber capacitor for the main switch, using a
ceramic capacitor with low ESR is important.
Layout Considerations
As for all switching power supplies, the layout is an important step in the design, especially at high peak currents
and high switching frequencies. If the layout is not carefully done, the regulator could show stability problems as
well as EMI problems. Therefore, use wide and short traces for the main current path and for the power ground
tracks. The input and output capacitor, as well as the inductor should be placed as close as possible to the IC.
Use a common ground node for power ground and a different one for control ground to minimize the effects of
ground noise. Connect these ground nodes at any place close to one of the ground pins of the IC.
The feedback divider should be placed as close as possible to the control ground pin of the IC. To lay out the
control ground, it is recommended to use short traces as well, separated from the power ground traces. This
avoids ground shift problems, which can occur due to superimposition of power ground current and control
ground current.
THERMAL INFORMATION
Implementation of integrated circuits in low-profile and fine-pitch surface-mount packages typically requires
special attention to power dissipation. Many system-dependent issues such as thermal coupling, airflow, added
heat sinks and convection surfaces, and the presence of other heat-generating components affect the
power-dissipation limits of a given component.
Three basic approaches for enhancing thermal performance are listed below.
•
•
•
Improving the power dissipation capability of the PCB design
Improving the thermal coupling of the component to the PCB
Introducing airflow in the system
The maximum recommended junction temperature (TJ) of the TPS6120x devices is 125°C. The thermal
resistance of the 10-pin QFN 3 × 3 package (DRC) is RθJA = 48.7 °C/W, if the PowerPAD is soldered. Specified
regulator operation is assured to a maximum ambient temperature TA of 85°C. Therefore, the maximum power
dissipation is about 820 mW. More power can be dissipated if the maximum ambient temperature of the
application is lower.
T
* T
J(MAX)
R
A
125°C * 85°C
48.7 °CńW
P
+
+
+ 820 mW
D(MAX)
qJA
(6)
17
Submit Documentation Feedback
PACKAGE OPTION ADDENDUM
www.ti.com
26-Jun-2007
PACKAGING INFORMATION
Orderable Device
TPS61200DRCR
TPS61200DRCRG4
TPS61200DRCT
Status (1)
ACTIVE
ACTIVE
ACTIVE
ACTIVE
ACTIVE
ACTIVE
ACTIVE
ACTIVE
ACTIVE
ACTIVE
ACTIVE
ACTIVE
Package Package
Pins Package Eco Plan (2) Lead/Ball Finish MSL Peak Temp (3)
Qty
Type
Drawing
SON
DRC
10
10
10
10
10
10
10
10
10
10
10
10
3000 Green (RoHS & CU NIPDAU Level-2-260C-1 YEAR
no Sb/Br)
SON
SON
SON
SON
SON
SON
SON
SON
SON
SON
SON
DRC
DRC
DRC
DRC
DRC
DRC
DRC
DRC
DRC
DRC
DRC
3000 Green (RoHS & CU NIPDAU Level-2-260C-1 YEAR
no Sb/Br)
250 Green (RoHS & CU NIPDAU Level-2-260C-1 YEAR
no Sb/Br)
TPS61200DRCTG4
TPS61201DRCR
TPS61201DRCRG4
TPS61201DRCT
250 Green (RoHS & CU NIPDAU Level-2-260C-1 YEAR
no Sb/Br)
3000 Green (RoHS & CU NIPDAU Level-2-260C-1 YEAR
no Sb/Br)
3000 Green (RoHS & CU NIPDAU Level-2-260C-1 YEAR
no Sb/Br)
250 Green (RoHS & CU NIPDAU Level-2-260C-1 YEAR
no Sb/Br)
TPS61201DRCTG4
TPS61202DRCR
TPS61202DRCRG4
TPS61202DRCT
250 Green (RoHS & CU NIPDAU Level-2-260C-1 YEAR
no Sb/Br)
3000 Green (RoHS & CU NIPDAU Level-2-260C-1 YEAR
no Sb/Br)
3000 Green (RoHS & CU NIPDAU Level-2-260C-1 YEAR
no Sb/Br)
250 Green (RoHS & CU NIPDAU Level-2-260C-1 YEAR
no Sb/Br)
TPS61202DRCTG4
250 Green (RoHS & CU NIPDAU Level-2-260C-1 YEAR
no Sb/Br)
(1) The marketing status values are defined as follows:
ACTIVE: Product device recommended for new designs.
LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect.
NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in
a new design.
PREVIEW: Device has been announced but is not in production. Samples may or may not be available.
OBSOLETE: TI has discontinued the production of the device.
(2)
Eco Plan - The planned eco-friendly classification: Pb-Free (RoHS), Pb-Free (RoHS Exempt), or Green (RoHS & no Sb/Br) - please check
http://www.ti.com/productcontent for the latest availability information and additional product content details.
TBD: The Pb-Free/Green conversion plan has not been defined.
Pb-Free (RoHS): TI's terms "Lead-Free" or "Pb-Free" mean semiconductor products that are compatible with the current RoHS requirements
for all 6 substances, including the requirement that lead not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered
at high temperatures, TI Pb-Free products are suitable for use in specified lead-free processes.
Pb-Free (RoHS Exempt): This component has a RoHS exemption for either 1) lead-based flip-chip solder bumps used between the die and
package, or 2) lead-based die adhesive used between the die and leadframe. The component is otherwise considered Pb-Free (RoHS
compatible) as defined above.
Green (RoHS & no Sb/Br): TI defines "Green" to mean Pb-Free (RoHS compatible), and free of Bromine (Br) and Antimony (Sb) based flame
retardants (Br or Sb do not exceed 0.1% by weight in homogeneous material)
(3)
MSL, Peak Temp. -- The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder
temperature.
Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is
provided. TI bases its knowledge and belief on information provided by third parties, and makes no representation or warranty as to the
accuracy of such information. Efforts are underway to better integrate information from third parties. TI has taken and continues to take
reasonable steps to provide representative and accurate information but may not have conducted destructive testing or chemical analysis on
incoming materials and chemicals. TI and TI suppliers consider certain information to be proprietary, and thus CAS numbers and other limited
information may not be available for release.
Addendum-Page 1
PACKAGE OPTION ADDENDUM
www.ti.com
26-Jun-2007
In no event shall TI's liability arising out of such information exceed the total purchase price of the TI part(s) at issue in this document sold by TI
to Customer on an annual basis.
Addendum-Page 2
PACKAGE MATERIALS INFORMATION
www.ti.com
16-Jul-2007
TAPE AND REEL INFORMATION
Pack Materials-Page 1
PACKAGE MATERIALS INFORMATION
www.ti.com
16-Jul-2007
Device
Package Pins
Site
Reel
Reel
A0 (mm)
B0 (mm)
K0 (mm)
P1
W
Pin1
Diameter Width
(mm) (mm) Quadrant
(mm)
330
330
330
330
330
330
(mm)
12
TPS61200DRCR
TPS61200DRCT
TPS61201DRCR
TPS61201DRCT
TPS61202DRCR
TPS61202DRCT
DRC
DRC
DRC
DRC
DRC
DRC
10
10
10
10
10
10
FRB
FRB
FRB
FRB
FRB
FRB
3.3
3.3
3.3
3.3
3.3
3.3
3.3
3.3
3.3
3.3
3.3
3.3
1.6
1.6
1.6
1.6
1.6
1.6
8
8
8
8
8
8
12
12
12
12
12
12
Q2
Q2
Q2
Q2
Q2
Q2
12
12
12
12
12
TAPE AND REEL BOX INFORMATION
Device
Package
Pins
Site
Length (mm) Width (mm) Height (mm)
TPS61200DRCR
TPS61200DRCT
TPS61201DRCR
TPS61201DRCT
TPS61202DRCR
TPS61202DRCT
DRC
DRC
DRC
DRC
DRC
DRC
10
10
10
10
10
10
FRB
FRB
FRB
FRB
FRB
FRB
342.9
342.9
342.9
342.9
342.9
342.9
336.6
336.6
336.6
336.6
336.6
336.6
20.64
20.64
20.64
20.64
20.64
20.64
Pack Materials-Page 2
PACKAGE MATERIALS INFORMATION
www.ti.com
16-Jul-2007
Pack Materials-Page 3
IMPORTANT NOTICE
Texas Instruments Incorporated and its subsidiaries (TI) reserve the right to make corrections, modifications, enhancements,
improvements, and other changes to its products and services at any time and to discontinue any product or service without notice.
Customers should obtain the latest relevant information before placing orders and should verify that such information is current and
complete. All products are sold subject to TI’s terms and conditions of sale supplied at the time of order acknowledgment.
TI warrants performance of its hardware products to the specifications applicable at the time of sale in accordance with TI’s
standard warranty. Testing and other quality control techniques are used to the extent TI deems necessary to support this
warranty. Except where mandated by government requirements, testing of all parameters of each product is not necessarily
performed.
TI assumes no liability for applications assistance or customer product design. Customers are responsible for their products and
applications using TI components. To minimize the risks associated with customer products and applications, customers should
provide adequate design and operating safeguards.
TI does not warrant or represent that any license, either express or implied, is granted under any TI patent right, copyright, mask
work right, or other TI intellectual property right relating to any combination, machine, or process in which TI products or services
are used. Information published by TI regarding third-party products or services does not constitute a license from TI to use such
products or services or a warranty or endorsement thereof. Use of such information may require a license from a third party under
the patents or other intellectual property of the third party, or a license from TI under the patents or other intellectual property of TI.
Reproduction of TI information in TI data books or data sheets is permissible only if reproduction is without alteration and is
accompanied by all associated warranties, conditions, limitations, and notices. Reproduction of this information with alteration is an
unfair and deceptive business practice. TI is not responsible or liable for such altered documentation. Information of third parties
may be subject to additional restrictions.
Resale of TI products or services with statements different from or beyond the parameters stated by TI for that product or service
voids all express and any implied warranties for the associated TI product or service and is an unfair and deceptive business
practice. TI is not responsible or liable for any such statements.
TI products are not authorized for use in safety-critical applications (such as life support) where a failure of the TI product would
reasonably be expected to cause severe personal injury or death, unless officers of the parties have executed an agreement
specifically governing such use. Buyers represent that they have all necessary expertise in the safety and regulatory ramifications
of their applications, and acknowledge and agree that they are solely responsible for all legal, regulatory and safety-related
requirements concerning their products and any use of TI products in such safety-critical applications, notwithstanding any
applications-related information or support that may be provided by TI. Further, Buyers must fully indemnify TI and its
representatives against any damages arising out of the use of TI products in such safety-critical applications.
TI products are neither designed nor intended for use in military/aerospace applications or environments unless the TI products are
specifically designated by TI as military-grade or "enhanced plastic." Only products designated by TI as military-grade meet military
specifications. Buyers acknowledge and agree that any such use of TI products which TI has not designated as military-grade is
solely at the Buyer's risk, and that they are solely responsible for compliance with all legal and regulatory requirements in
connection with such use.
TI products are neither designed nor intended for use in automotive applications or environments unless the specific TI products
are designated by TI as compliant with ISO/TS 16949 requirements. Buyers acknowledge and agree that, if they use any
non-designated products in automotive applications, TI will not be responsible for any failure to meet such requirements.
Following are URLs where you can obtain information on other Texas Instruments products and application solutions:
Products
Amplifiers
Data Converters
DSP
Applications
Audio
amplifier.ti.com
dataconverter.ti.com
dsp.ti.com
www.ti.com/audio
Automotive
Broadband
Digital Control
Military
www.ti.com/automotive
www.ti.com/broadband
www.ti.com/digitalcontrol
www.ti.com/military
Interface
interface.ti.com
logic.ti.com
Logic
Power Mgmt
Microcontrollers
RFID
power.ti.com
Optical Networking
Security
www.ti.com/opticalnetwork
www.ti.com/security
www.ti.com/telephony
www.ti.com/video
microcontroller.ti.com
www.ti-rfid.com
www.ti.com/lpw
Telephony
Low Power
Wireless
Video & Imaging
Wireless
www.ti.com/wireless
Mailing Address: Texas Instruments, Post Office Box 655303, Dallas, Texas 75265
Copyright © 2007, Texas Instruments Incorporated
相关型号：
©2020 ICPDF网 联系我们和版权申明