TI TPS65155RKPR

TPS65155
SLVSB29 – JANUARY 2012
www.ti.com
LCD Bias Solution with Level Shifters for GOA Panels
Check for Samples: TPS65155
FEATURES
DESCRIPTION
•
•
•
•
•
The TPS65155 provides an integrated bias and level
shifter solution for GOA panels.
1
•
•
•
•
•
•
•
3 V to 6 V Input Voltage Range
Boost Converter With 4 A Switch Current Limit
Boost Converter Output Voltages up to 18 V
Boost Converter Overvoltage Protection
Selectable Switching Frequency (640 kHz or
1.2 MHz)
Programmable Boost Converter Soft-Start
Temperature-Compensated Positive Charge
Pump Controller
Negative Charge Pump Controller
4 + 2 Channels of Level Shifters
XAO Reset Signal
Thermal Shutdown
40-Pin 5×5 mm QFN Package
The device integrates a boost converter to generate
the source driver supply voltage (VAVDD), positive and
negative charge pump controllers to generate gate
driver ON (VGH) and OFF (VGL) voltages, and an
6-channel level shifter in a single IC. The positive
charge pump controller supports temperature
compensation to reduce VGH at high temperatures.
In addition to the above functions, the TPS65155
generates an additional active-low XAO reset output.
Supply sequencing during power-up can be controlled
by an externally generated enable signal.
VIN
3.3 V
APPLICATIONS
•
LCD Monitors or Notebook Panels using GOA
Technology
AVDD Boost Converter
AVDD
9 V/300 mA
Positive Charge Pump Controller
With Temperature Compensation
VGHM
24 V/20 mA
Negative Charge Pump Controller
VGL
-6 V/20 mA
Reset Function
XAO
4
4-phase level
shifter
2
STVOUT
RESETOUT
4
2
4 + 2 Channel
Level Shifter
1
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.
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
Copyright © 2012, Texas Instruments Incorporated
TPS65155
SLVSB29 – JANUARY 2012
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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.
ORDERING INFORMATION (1)
TA
ORDERING
PACKAGE
PACKAGE MARKING
–40°C to 85°C
TPS65155RKPR
40-Pin 5×5 QFN
TPS65155
(1)
The device is supplied taped and reeled, with 3000 devices per reel.
ABSOLUTE MAXIMUM RATINGS
over operating free-air temperature range (unless otherwise noted)
(1)
VALUE
Pin Voltage (2)
FBN, VREF, SCL, SDA, FBP, RESETIN, CLKIN1, CLKIN2, CLKIN3, CLKIN4, FBPH,
FREQ, COMP, FB, SS, VIN, DRVN, VDET, STVIN, RNTC, EN, XAO
7
AVDD, SW
20
DRVP, VGH
40
V
–20
VGL
–20 to 40
STVOUT, RESETOUT, CLKOUT1, CLKOUT2, CLKOUT3, CLKOUT4
Human Body Model
ESD Rating
UNIT
2
kV
Machine Model
200
V
Charged Device Model
500
V
PD
Continuous Power Dissipation
See Thermal Table
W
TA
Ambient temperature
–40 to 85
°C
TJ
Junction temperature
–40 to 150
°C
TSTG
Storage temperature
–65 to 150
°C
300
°C
Lead temperature (soldering, 10 seconds)
(1)
(2)
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.
With respect to the AGND and LGND pins.
THERMAL INFORMATION
TPS65155
THERMAL METRIC (1)
QFN
UNITS
40 PINS
θJA
Junction-to-ambient thermal resistance
36.1
θJC(top)
Junction-to-case(top) thermal resistance
30.0
θJB
Junction-to-board thermal resistance
10.5
ψJT
Junction-to-top characterization parameter
0.7
ψJB
Junction-to-board characterization parameter
10.5
θJC(bottom)
Junction-to-case(bottom) thermal resistance
4.6
(1)
2
°C/W
For more information about traditional and new thermal metrics, see the IC Package Thermal Metrics application report, SPRA953.
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RECOMMENDED OPERATING CONDITIONS
MIN
VIN
Input voltage range
VAVDD
Boost converter output voltage range
VGH
TYP MAX
5
UNIT
6
V
7 (1)
18
V
Level shifter positive supply voltage range
15
38
V
VGL
Level shifter negative supply voltage range
–3
–15
V
VDET
Panel discharge threshold voltage
CREF
VREF decoupling capacitance
220
nF
TA
TJ
(1)
3
2
V
10
100
Operating ambient temperature
–40
25
85
°C
Operating junction temperature
–40
85
125
°C
Or VIN + 1 V, whichever is lower.
ELECTRICAL CHARACTERISTICS
VIN = 5 V; VAVDD = 13.6 V, VGH = 28 V, VGL1 = VGL2 = –10 V, TA = –40°C to 85°C; FREQ = high. Typical values are at 25°C
(unless otherwise noted).
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNIT
POWER SUPPLY
IIN
VIN supply current
ISUP
Positive supply current
Device not switching, VFB = VL+ 5%
0.75
mA
0.04
mA
IGH
Positive supply current
IGL
Negative supply current
STVIN = 0 V, RESETIN = 0 V, CLKIN1-CLKIN4 = 0 V
0.26
mA
STVIN = 0 V, RESETIN = 0 V, CLKIN1-CLKIN4 = 0 V
0.035
VUVLO
UVLO threshold
VIN rising
2.5
mA
VHYS
UVLO hysteresis
VIN falling
0.25
VREF
External reference voltage
IL = 100 µA
IREF
Reference voltage maximum output current VL = 1.24 V ± 2%
1.215
1.24
V
V
1.265
V
µA
250
CONTROL SIGNALS (EN, FREQ)
VIH
High input voltage threshold
EN, FREQ rising
VIL
Low input voltage threshold
EN, FREQ falling
RPULL-UP
Pull-up resistor
EN, FREQ
VOL
Low level output voltage
IXAO = 1 mA, sinking
IOH
High level leakage current
VXAO = 5 V
2.0
0.5
V
V
50
kΩ
RESET (XAO)
0.5
V
2
µA
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ELECTRICAL CHARACTERISTICS (continued)
VIN = 5 V; VAVDD = 13.6 V, VGH = 28 V, VGL1 = VGL2 = –10 V, TA = –40°C to 85°C; FREQ = high. Typical values are at 25°C
(unless otherwise noted).
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNIT
18 (1)
V
20.0
V
BOOST CONVERTER (AVDD)
VAVDD
Output voltage
IAVDD = 0.5 A
VOVP
Overvoltage threshold
VAVDD rising
VOVP(HYS)
Overvoltage hysteresis
VAVDD falling
0.3
VAVDD rising, during power-up
2.6
VSCP(AVDD)
Short-circuit threshold voltage
VFB(PG)
Power good threshold
tSCP(AVDD)
Short circuit timer
VFB
Feedback regulation voltage
IFB
Feedback input bias current
gm
Error amplifier transconductance
rDS(ON)
Switch ON resistance
ILIM
Switch current limit
ILK
Switch leakage current
EN = 0 V, VSW = 18.5 V
ISS
Soft-start capacitor charge current
VSS = 1.24 V
fSW
Oscillator frequency
7
18.0
VFB falling, during normal operation
19.0
V
V
0.36
VFB rising
97
VFB falling
91.7
OFF time
55
ON time
15
1.228
1.240
–100
VFB = 1.24 V
4.0
ms
1.252
V
100
nA
140
µA/V
0.13
0.18
Ω
4.8
5.6
A
30
µA
80
VIN = 5 V, ISW = ILIM
% of
VREF
µA
4.4
FREQ connected to VIN
900
1200
1500
FREQ connected to 0V
470
640
790
Line regulation
VIN = 4 V to 6 V, IAVDD = 0.5 A
Load regulation
IAVDD = 0.1 A to 0.5 A
kHz
0.01
%/V
0.2
%/A
POSITIVE CHARGE PUMP CONTROLLER (VGH)
VDRVP
Base drive voltage range
IDRVP
Base drive sink current
VFBP
Feedback regulation voltage
With external pull-up resistor
40
Normal operation, sinking, VFBP = 1.575 V, VDRVP = 28 V
Short-circuit operation, sinking, VFBP = 0 V, VDRVP = 28 V
2.5
40
1.663
1.75
1.838
Lower limit; VRNTC = 1.5 V, VFBPH = 1.75 V
1.425
1.50
1.575
Lower limit; VRNTC = 1.0 V, VFBPH = 1.75 V
1.178
1.24
1.302
VFBP rising, during power-up
124
VFBP falling, during normal operation
340
VFBP rising
97.5
VFBP falling
92.5
Short circuit threshold voltage
VFBP(PG)
Power good threshold
tSCP(VGH)
Short circuit timer
Starts from boost converter power good
IFBP
FBP input bias current
VRNTC = 1 V, VFBPH = 1.75 V, VFBP = 1.24 V
IRNTC
RNTC output current
VRNTC = 1.5 V, matched to IFBPH; at TA = 25 °C
190
IFBPH
FBPH output current
VFBPH = 1.75 V, trimnmed; at TA = 25 °C
195
Load regulation
IGH = 1 mA to 50 mA
(1)
4
72
Lower limit; VRNTC = 2 V, VFBPH = 1.75 V
VFBP(SCP)
V
mA
V
mV
% of
VREF
15
–100
µA
ms
100
nA
200
210
µA
200
205
0.05
µA
%/mA
Limited by overvoltage protection function.
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ELECTRICAL CHARACTERISTICS (continued)
VIN = 5 V; VAVDD = 13.6 V, VGH = 28 V, VGL1 = VGL2 = –10 V, TA = –40°C to 85°C; FREQ = high. Typical values are at 25°C
(unless otherwise noted).
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNIT
NEGATIVE CHARGE PUMP CONTROLLER (VGL)
IDRVN
Base drive current
Normal operation, sourcing, VFBN = 25 mV, VDRVN = 0.7V
2.5
Short-circuit operation, sourcing, VFBN = 1.116 V,
VDRVN = 0.7 V
200
VFBN
Feedback regulation voltage
IDRVN = 1 mA, sourcing
IFBN
FBN input bias current
VFBN = 0 V
mA
480
µA
–15
15
mV
–100
100
nA
300
VFBN falling, during start-up
794
VFBN rising, during normal operation
817
VFBN falling
2.8
VFBN rising
7.5
VFBN(SCP)
Short circuit threshold voltage
VFBN(PG)
Power good threshold
tSCP(VGL)
Short circuit timer
Starts from boost converter power good
Load regulation
IGL1 = 1 mA to 50 mA
mV
% of
VREF
15
ms
0.05
%/mA
LEVEL SHIFTERS (CLK1 to CLK4)
VUVLO
UVLO threshold
VGH rising.
VIH
Level shifter high level input threshold
VCLKINx rising
VIL
Level shifter low level input threshold
VCLKINx falling
High side ON resistance
ICLKOUTx = 10 mA, sourcing
Low side ON resistance
ICLKOUTx = 10 mA, sinking
rDS(ON)
5.0
7.5
10.0
V
1.5
V
0.5
V
14
Ω
8
LEVEL SHIFTERS (STV, RESET)
VIH
Level shifter high level input threshold
VSTVIN, VRESETIN rising
VIL
Level shifter low level input threshold
VSTVIN, VRESETIN falling
High side ON resistance
ISTVOUT, IRESETOUT = 10 mA, sourcing
35
Low side ON resistance
ISTVOUT, IRESETOUT = 10 mA, sinking
15
rDS(ON)
1.5
0.5
V
V
Ω
I2C INTERFACE
Bus address
4Fh
VIL
Low level input voltage
VIN = 4 V to 6 V
0.7
VIH
High level input voltage
VIN = 4 V to 6 V
1.5
V
V
VOL
Low level output voltage
Sinking 3 mA
0.4
V
THERMAL SHUTDOWN
TSD
Thermal shutdown threshold
THYS
Thermal shutdown hysteresis
138
°C
8
°C
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DEVICE INFORMATION
6
FBPH
RNTC
DRVP
FBP
DRVN
VREF
FBN
VGL
VGH
CLKIN1
40
39
38
37
36
35
34
33
32
31
PIN ASSIGNMENT
COMP
1
30
CLKIN 2
AGND
2
29
ClKIN 3
SS
3
28
CLKIN 4
NC
4
27
STVIN
FB
5
26
RESETIN
25
NC
ePAD
19
20
CLKOUT2
CLKOUT 3
CLKOUT1
21
18
10
LGND
XAO
17
CLKOUT 4
SDA
22
16
9
SCL
VIN
15
STVOUT
GND
23
14
8
AVDD
FREQ
13
RESETOUT
GND
24
12
7
VDET
SW
11
6
EN
PGND
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PIN FUNCTIONS
PIN
I/O
DESCRIPTION
NAME
NO.
COMP
1
I
Boost converter compensation
AGND
2
P
Analog ground
SS
3
I
Boost converter soft-start capacitor connection
NC
4
O
No connection. Leave the pin floating
FB
5
I
Boost converter feedback
PGND
6
P
Power ground
SW
7
P
Boost converter switch node
FREQ
8
I
Boost converter frequency select
VIN
9
P
Supply voltage
/XAO
10
O
Reset
EN
11
I
Device enable
VDET
12
I
Panel discharge input
GND
13
I
Ground
AVDD
14
P
High voltage analog supply
GND
15
I
Ground
SCL
16
I/O
I2C interface clock
SDA
17
I/O
I2C interface data
LGND
18
P
Level shifter ground connection
CLKOUT1
19
O
Level shifter input
CLKOUT2
20
O
Level shifter input
CLKOUT3
21
O
Level shifter input
CLKOUT4
22
O
Level shifter input
STVOUT
23
O
Level shifter input
RESETOUT
24
O
Level shifter input
NC
25
RESETIN
26
I
Level shifter input
STVIN
27
I
Level shifter input
CLKIN4
28
I
Level shifter input
CLKIN3
29
I
Level shifter input
CLKIN2
30
I
Level shifter input
CLKIN1
31
I
Level shifter input
VGH
32
P
Level shifter positive supply
VGL
33
P
Level shifter negative supply
FBN
34
I
Negative charge pump regulator feedback
VREF
35
O
Internal voltage reference
DRVN
36
O
Negative charge pump regulator drive signal (connects to base of external NPN transistor)
FBP
37
I
Positive charge pump regulator feedback
DRVP
38
O
Positive charge pump regulator drive signal (connects to base of external PNP transistor)
RNTC
39
I
Positive charge pump LDO thermistor connection
FBPH
40
I
Positive charge pump LDO temperature-setting resistor connection
P
Exposed pad. Connect to the system GND
ePAD
No connection. Leave this pin floating.
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TYPICAL CHARACTERISTICS
TABLE OF GRAPHS
FIGURE
BOOST CONVERTER
VIN = 5 V, VAVDD = 13.6 V, IAVDD = 0 A to 1 A
Figure 1
VIN = 5 V, VAVDD = 18 V, IAVDD = 0 A to 1 A
Figure 2
vs Load current
VIN = 5 V, VAVDD = 13.6 V, IAVDD = 0 A to 0.8 A
Figure 3
vs Supply voltage
VIN = 3.5 V to 6.0 V, VAVDD = 13.6 V, IAVDD = 0.5 A
Figure 4
fSW=1.2MHz, L=4.7µH
VIN = 5 V, VAVDD = 13.6 V (10 V transient)
Figure 5
Load Transient
Response
fSW=640kHz, L=10µH
VIN = 5 V, VAVDD = 13.6 V, IAVDD = 250 mA/750 mA step
Figure 6
Soft-start
CSS=22nF
Overvoltage
Protection
Duration = 75 ms
Efficiency
Frequency
Undervoltage
Protection
fSW=1.2MHz, L=4.7µH
Figure 7
VIN = 5 V, VAVDD = 13.6 V, IAVDD = 0.5 A
Figure 8
Figure 9
Short-Circuit
Protection
Duration = 75 ms
VIN = 5 V, VAVDD = 13.6 V, IAVDD = 0.5 A
Figure 10
Duration = 25 ms
VIN = 5 V, VAVDD = 13.6 V, IAVDD = 0.5 A
Figure 11
Switch Node
Waveform
CCM operation
VIN = 5 V, VAVDD = 13.6 V, IAVDD = 0.5 A
Figure 12
DCM operation
VIN = 5 V, VAVDD = 13.6V, IAVDD = 0.1A
Figure 13
VIN = 5V, VAVDD = 13.6V, IAVDD = 0.5A VGH = 28V,
IGH = 10 mA/50 mA step
Figure 14
POSITIVE CHARGE PUMP
Load Transient
Response
fSW = 640kHz, L = 10µH
fSW = 1.2MHz, L = 4.7µH
VIN = 4 V to 6 V, VAVDD = 13.6 V, IAVDD = 0.5A,
VGH(COLD) = 28 V, VGH(HOT) = 24 V, TCOLD = -10°C,
THOT = 10°C, IGH = 25 mA
Temperature
Compensation
Figure 15
Figure 16
NEGATIVE CHARGE PUMP
Load Transient
Response
fSW = 640kHz, L = 10µH
fSW = 1.2MHz, L = 4.7µH
VIN = 5 V, VAVDD = 13.6 V, IAVDD = 0.5 A, VGL = –10 V,
IGL = 10 mA/50 mA step
Figure 17
Figure 18
START-UP SEQUENCING
Power-Up Sequence
VIN, VAVDD, VGH, VGL
VIN = 5V, VAVDD = 13.6 V, VGH = 28 V, VGL = –10 V
Figure 19
Power-Up Sequence
VIN, CLKOUTx, STVOUT,
RESETOUT
VIN = 5V, VAVDD = 13.6 V, VGH = 28 V, VGL = –10 V
Figure 20
Power-Down
Sequence
VIN, CLKOUTx, STVOUT,
RESETOUT
VIN = 5V, VAVDD = 13.6 V, VGH = 28 V, VGL = –10 V
Figure 21
LEVEL SHIFTERS
Peak Output Current
Rise Time
Fall Time
8
CLKOUTx
STVOUT, RESETOUT
CLKOUTx
STVOUT, RESETOUT
CLKOUTx
STVOUT, RESETOUT
VGH = 28V, VGL = –10V, 10 nF load
VGH = 28 V, VGL = –10 V, 47Ω + 10 nF load
VGH = 28 V, VGL = –10 V, 47Ω + 10 nF load
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Figure 22
Figure 23
Figure 24
Figure 25
Figure 26
Figure 27
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BOOST CONVERTER EFFICIENCY (VAVDD = 13.6 V)
BOOST CONVERTER EFFICIENCY (VAVDD = 18 V)
100
100
FREQ = Low
FREQ = Low
90
90
80
80
FREQ = High
70
Efficiency – %
Efficiency – %
70
60
50
40
FREQ = High
60
50
40
30
30
20
20
10
10
0
0
0.0
0.2
0.4
0.6
0.8
1.0
0.0
0.4
0.6
IAVDD – Output Voltage Current – A
Figure 1.
Figure 2.
BOOST CONVERTER FREQUENCY vs. LOAD CURRENT
0.8
1.0
BOOST CONVERTER FREQUENCY vs. SUPPLY VOLTAGE
1400
1400
FREQ = High
FREQ = High
1200
1200
Boost Switching Frequency – kHz
Boost Converter Frequency – kHz
0.2
IAVDD – Output Voltage Current – A
1000
800
FREQ = Low
600
400
200
0
1000
800
FREQ = Low
600
400
200
0
0
100
200
300
400
500
600
700
800
3.5
Output Current – mA
4.0
4.5
5.0
5.5
6.0
VIN – Input Voltage – V
Figure 3.
Figure 4.
BOOST CONVERTER UNDERVOLTAGE PROTECTION
BOOST CONVERTER LOAD TRANSIENT RESPONSE
Converter Load
AVDD
AVDD
Converter O/P
IAVDD
AVDD
fSW=640kHz, L=10µH
Figure 5.
Figure 6.
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BOOST CONVERTER LOAD TRANSIENT RESPONSE
BOOST CONVERTER SOFT-START
AVDD
AVDD
IIN
IAVDD
fSW=1.2MHz, L=4.7µH
Figure 7.
Figure 8.
BOOST CONVERTER OVERVOLTAGE PROTECTION
BOOST CONVERTER SHORT-CIRCUIT PROTECTION
AVDD
Short
Circuit
Duration
AVDD
VSW
VGD
Figure 9.
Figure 10.
BOOST CONVERTER SHORT-CIRCUIT PROTECTION
BOOST CONVERTER SWITCH NODE WAVEFORM (CCM)
AVDD
VSW
VGD
IL
Figure 11.
10
Figure 12.
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BOOST CONVERTER SWITCH NODE WAVEFORM (DCM)
POSITIVE CHARGE PUMP LOAD TRANSIENT RESPONSE
VGH
VSW
IGH
fSW=640kHz, L=10µH
IL
Figure 13.
Figure 14.
POSITIVE CHARGE PUMP LOAD TRANSIENT RESPONSE
POSITIVE CHARGE PUMP TEMPERATURE
COMPENSATION
VGH
IGH
VGH – Level Shifter Voltage Range – V
28.5
27.5
27.0
26.5
26.0
25.5
25.0
24.5
24.0
23.5
-20
fSW=1.2MHz, L=4.7µH
VGH(HOT) = 28 V
VGH(COLD) = 24 V
TCOLD = –10 °C
THOT = 10 °C
28.0
-15
-10
-5
0
5
10
15
20
Temperature – °C
Figure 15.
Figure 16.
NEGATIVE CHARGE PUMP LOAD TRANSIENT RESPONSE
NEGATIVE CHARGE PUMP LOAD TRANSIENT RESPONSE
VGL
VGL
IGL
IGL
fSW=640kHz, L=10µH
Figure 17.
fSW=1.2MHz, L=4.7µH
Figure 18.
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POWER-UP SEQUENCE #1
POWER-UP SEQUENCE #2
VIN
VIN
AVDD
VCLKOUTx
VGH
VSTVOUT
VRESETOUT
VGL
Figure 19.
Figure 20.
POWER-DOWN SEQUENCE #1
PEAK OUTPUT CURRENT (CLKx)
VIN
544mA
VCLKOUTx
ICLKOUT1
VSTVOUT
VRESETOUT
564mA
Figure 21.
Figure 22.
PEAK OUTPUT CURRENT (STVOUT, RESETOUT)
RISE TIME (CLKOUTx)
258mA
VCLKOUT1
ISTVOUT
302mA
Load=47Ω+10nF
Figure 23.
12
Figure 24.
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RISE TIME (STVOUT, RESETOUT)
FALL TIME (CLKOUTx)
VSTVOUT
VCLKOUT1
Load=47Ω+10nF
Load=47Ω+10nF
Figure 25.
Figure 26.
FALL TIME (STVOUT, RESETOUT)
VSTVOUT
Load=47Ω+10nF
Figure 27.
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DETAILED DESCRIPTION
An internal block diagram of the TPS65155 is shown in Figure 28.
SS
SW
COMP
EN
VAVDD
+
VOVP
-
Boost
Converter
PGND
FREQ
FB
+
VPG
+
DRVP
EN
-
VIN
VIN
+
VUVLO
-
FBP
Internal
Bias
Temperature
Compensation
AGND
XAO
RNTC
FBPH
Buffer
VREF
VIN
+
DRVN
FBN
Discharge
+
VGH
VDET
VREF
STVOUT
STVIN
RESETOUT
RESETIN
CLKOUT1
CLKIN1
CLKIN2
Level
Shifter
CLKIN3
CLKOUT2
CLKOUT3
CLKOUT4
CLKIN4
LGND
VGL
EEPROM
SDA
SCL
2
IC
Interface
LOGIC
Note:
For clarity, duplicate pins not shown.
Figure 28. Internal Block Diagram
14
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Boost Converter
An internal block diagram of the boost converter is contained in Figure 29.
L1
D1
VAVDD
VIN
C1
EN
C2
VIN
SW
AVDD
VOVP
-
FREQ
+
Bias
UVLO
Thermal SD
R1
tOFF
Generator
SS
Current Limit
& Soft Start
+
FB
R2
PWM
Generator
C4
+
COMP
VREF
R4
PGND
C5
C3
Figure 29. Boost Converter Internal Block Diagram
The boost converter is designed for output voltages up to 18V with a switch current limit of 4 A (guaranteed
minimum). The converter uses a current mode, quasi-constant frequency topology, and is externally
compensated for maximum flexibility. A soft-start feature limits the current drawn from VIN during start-up, and
the converter's switching frequency can be selected between 640 kHz and 1.2 MHz.
The converter's adaptive off-time topology achieves superior transient response and operates over a wider range
of applications than conventional converters.
Design Procedure (Boost Converter)
The first step in the design procedure is to calculate the peak switch current. The simplest way to do this is to
use the curves in the typical characteristics section to estimate converter efficiency in the intended application.
Alternatively, a conservative worst-case value such as 85% can be used.
Once a value for the converter's efficiency η is available, Equation 1 can be used to calculate its duty cycle.
V ´ η
D = 1 - IN
VAVDD
(1)
The next step is to use Equation 2 to calculate the change in inductor current per cycle.
V ´ D
ΔIL = IN
¦ ´ L
(2)
Finally, the peak switch current can be calculated using Equation 3.
IS W (P K) =
IA VDD
1 - D
+
ΔIL
(3)
2
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The value for peak switch current calculated using Equation 3 must be lower than the minimum specified for the
device, and should be calculated under worst-case conditions (minimum VIN and maximum IAVDD).
Inductor Selection (Boost Converter)
The boost converter in the TPS65155 has been optimized for inductors in the range 3.3 µH to 6.8 µH when using
the higher switching frequency and in the range 7 µH to 13 µH when using the lower switching frequency.
The saturation current of the inductor must be greater than the peak switch current plus an additional margin to
allow for heavy load transients. A saturation current of 130% of the value calculated using Equation 3 is
adequate for most applications.
Table 1 shows a selection of inductors suitable for use with the TPS65155.
Table 1. Boost Converter Inductor Selection
INDUCTANCE
MANUFACTURER
PART NUMBER
SIZE
DCR
ISAT
1.2 MHz OPERATION
4.7 µH
Coiltronics
UP2B-4R7-R
14.0 × 10.4 × 6.0
17 mΩ
5.5 A
4.7 µH
Sumida
CDRH12NP-4R7-M
12.3 × 12.3 × 4.5
18 mΩ
5.7 A
4.7 µH
Sumida
CDRH127
12.3 × 12.3 × 8.0
12 mΩ
6.8 A
10 µH
Coilcraft
DS3316P
13.0 × 9.4 × 5.1
70 mΩ
3.5 A
10 µH
Sumida
CDRH8D43
8.3 × 8.3 × 4.5
29 mΩ
4.0 A
10 µH
Sumida
CDRH127
12.3 × 12.3 × 8.0
16 mΩ
5.4 A
10 µH
Sumida
CDRH127LD
12.3 × 12.3 × 8.0
15 mΩ
6.7 A
640 kHz OPERATION
Rectifier Selection (Boost Converter)
A Schottky type is recommended for the boost converter rectifier diode because its low forward voltage improves
efficiency. The diode's reverse voltage rating must be greater than 20 V, which is the maximum it will experience
(the TPS65155's overvoltage protection function prevents this voltage being any higher). The diode's average
rectified current rating must be at least as high as the maximum IAVDD. A 2 A rating is sufficient for most
applications.
Equation 4 can be used to calculate the power dissipated in the diode. The diode must be capable of handling
this power without overheating. A power rating of 500 mW is sufficient for most applications.
P = VF ´ IAVDD
(4)
Where:
VF is the diode's forward voltage
IAVDD is the average (mean) boost converter output current
Table 2 shows a selection of rectifier diodes suitable for use with the TPS65155.
Table 2. Boost Converter Rectifier Selection
CURRENT
MANUFACTURER
PART NUMBER
SIZE
VR
VF
2A
2A
Vishay
SL22
SMA
20 V
0.44 V at 2 A
Vishay
SS22
SMA
20 V
0.5 V at 2 A
Input Capacitor Selection (Boost Converter)
For good supply voltage filtering, low ESR capacitors are recommended. The TPS65155 has an analog supply
voltage pin (VIN) that should be decoupled with a ceramic capacitor in the range 100 nF to 1 µF, connected
close to the VIN pin.
The main boost converter (i.e. where VIN is connected to the inductor of the boost converter) should also be
decoupled. Two 10 µF or one 22 µF ceramic capacitor are adequate for most applications, however, these
values can be increased if improved filtering is required.
16
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Setting the Output Voltage (Boost Converter)
The output voltage of the boost converter is set by a resistor divider connected to the FB pin. The boost
converter's main error amplifier compares the feedback voltage with the internal reference voltage VREF so that
the output is regulated at a voltage given by Equation 5.
æR
ö
VAVDD = 1.24 × ç 1 + 1÷
è R2
ø
(5)
Soft-Start (Boost Converter)
To reduce the inrush current drawn from VIN during start-up the boost converter includes a soft-start feature.
Soft-start is controlled by a capacitor connected to the soft-start (SS) pin. During soft-start, this capacitor is
charged up by a current source and the voltage across the capacitor determines the switch current limit: the
larger the capacitor, the slower the ramp of the switch current limit and therefore the longer the soft-start time.
The maximum switch current limit is achieved when the voltage connected to the boost converter's feedback pin
(FB) reaches its power good threshold (approximately 97 percent of its nominal value).
A 22 nF soft-start capacitor is suitable for most applications.
When the EN pin is pulled low, the soft-start capacitor is discharged.
Frequency Select (FREQ)
The frequency select (FREQ) pin can be used to set the nominal boost converter switching frequency to either
640 kHz (FREQ=low) or 1.2 MHz (FREQ=high). A higher switching frequency improves the load transient
response and output voltage ripple; a lower switching frequency usually improves efficiency.
A switching frequency of 1.2 MHz is recommended for most applications unless efficiency is the primary concern.
The FREQ pin features an internal pull-up resistor that ensures the higher switching frequency is used if the pin
is left floating.
Compensation (COMP)
The boost converter uses an external compensation network connected to its COMP pin to stabilize its feedback
loop. The COMP pin is connected to the output of the boost converter's transconductance error amplifier, and a
series resistor and capacitor connected between this pin and AGND is sufficient to achieve good performance in
most applications. The capacitor primarily influences low frequency gain and the resistor primarily influences high
frequency gain. Lower output voltages require higher loop gain and therefore a larger compensation capacitor.
Good starting values, which will work for most applications running from a 5 V supply voltage, are 47 kΩ and 3.3
nF.
In some applications (e.g. those using electrolytic output capacitors), it may be necessary to include a second
compensation capacitor between the COMP pin and AGND. This has the effect of adding an additional pole in
the feedback loop's frequency response, which can be used to cancel the zero introduced by the electrolytic
output capacitor's ESR. It is recommended to include a footprint on the PCB for this optional capacitor, even if it
is not used initially.
Overvoltage Protection (Boost Converter)
The boost converter contains an overvoltage protection (OVP) feature that limits its output voltage to a safe
maximum if the FB pin is floating or shorted to ground. Overvoltage conditions are detected when the voltage
applied to the AVDD pin (VAVDD) exceeds the overvoltage threshold (VOVP). As soon as this happens, the boost
converter switch is turned off. It remains off until VAVDD falls below VOVP (minus hysteresis), at which point the
boost converter automatically starts switching again.
NOTE
The AVDD pin must be connected to the boost converter output for the overvoltage
protection feature to operate correctly.
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Short-Circuit and Undervoltage Protection (Boost Converter)
During normal operation (i.e., once the boost converter has reached its power good threshold) a short circuit is
detected if the feedback voltage VFB falls below 30% of VREF. If this happens, the boost converter is disabled.
Either VIN or EN must be cycled to recover normal operation.
Undervoltage Lockout Protection (Boost Converter)
During operation, if the output of the boost converter falls below its power good threshold for longer than 55ms,
the TPS65155 will detect an undervoltage condition and turn itself off. VIN or EN must be cycled to recover
normal operation.
Positive Charge Pump
Figure 30 shows the internal block diagram of the positive charge pump.
The positive charge pump is driven directly from the boost converter's switch node and then post-regulated by an
external PNP transistor. The controller is optimized for transistors having a DC gain (hFE) in the range 100 to
300. The positive charge pump is temperature compensated so that its output voltage decreases at high
temperatures (see Figure 16).
SW
VAVDD
1.15V*
+
-
55 ms
Timer
VREF
200µA
200µA
VREF
UVP (Normal)
340mV*
+
SCP (Normal)
124mV*
+
Control
Logic
55µA
VGH
Normal
2.5 mA
R15
+
x1
VREF
Clamp
Error
Amplifier
FBP
R16
FBPH
R10
R11
R12
DRVP
SCP (Start-Up)
-
RNTC
Short
Circuit
RNTC
Figure 30. Positive Charge Pump Internal Block Diagram
Setting the Output Voltage (Positive Charge Pump)
The positive charge pump in the TPS65155 is temperature compensated such that its output voltage decreases
at high temperatures (see Figure 31). For a detailed description about how to set the output voltage see
Temperature Compensation section below.
18
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A current of the order of 1 mA through the feedback resistor network ensures good accuracy and increases the
circuit's immunity to noise. It also ensures a minimum load on the charge pump, which reduces output voltage
ripple under no-load conditions. A good approach is to assume a value of about 1.2 k for the lower resistor (R16)
and then select the upper resistor (R15) to set the desired output voltage.
Note that the maximum voltage in an application is determined by the boost converter's output voltage and the
voltage drop across the diodes and PNP transistor. For a typical application in which the positive charge pump is
configured as a voltage doubler, the maximum output voltage is given by Equation 6.
VGH(MAX) = (2 ´ VAVDD ) - (2 × VF ) - VCE
(6)
Where VAVDD is the output voltage of the boost converter, VF is the forward voltage of each diode and VCE is the
collector-emitter voltage of the PNP transistor (recommended to be at least 1 V, to avoid transistor saturation).
Selecting the PNP Transistor (Positive Charge Pump)
The PNP transistor used to regulate VGH should have a DC gain (hFE) of at least 100 when its collector current is
equal to the charge pump's output current. The transistor should also be able to withstand voltages up to VGH
across its collector-emitter junction (VCE).
The power dissipated in the transistor is given by Equation 7. The transistor must be able to dissipate this power
without its junction becoming too hot. Note that the ability to dissipate power depends heavily on adequate PCB
thermal design.
PQ = éë (2 ´ VAVDD ) - (2 ´ VF ) - VGH ùû ´ IGH
(7)
Where IGH is the mean (not RMS) output current drawn from the charge pump.
A pull-up resistor is also required between the transistor's base and emitter. The value of this resistor is not
critical, but it should be large enough not to divert significant current away from the base of the transistor. A
value of 100 kΩ is suitable for most applications.
Selecting the Diodes (Positive Charge Pump)
Small-signal diodes can be used for most low current applications (<50 mA) and higher rated diodes for higher
power applications. The average current through the diode is equal to the output current, so that the power
dissipated in the diode is given by Equation 8.
PD = IGH ´ VF
(8)
The peak current through the diode occurs during start-up and for a few cycles may be as high as a few amps.
However, this condition typically lasts for <1 ms and can be tolerated by many diodes whose repetitive current
rating is much lower. The diodes' reverse voltage rating should be equal to two times VAVDD.
Table 3. Positive Charge Pump Diode Selection
PART NUMBER
IAVG
IPK
VR
VF
BAV99W
150 mA
1 A for 1 ms
75 V
1 V at 50 mA
COMPONENT SUPPLIER
NXP
BAT54S
200 mA
600 mA for 1s
30 V
0.8 V at 100 mA
Fairchild Semiconductor
MBR0540
500 mA
5.5 A for 8 ms
40 V
0.51 at 500 mA
Fairchild Semiconductor
Selecting the Capacitors (Positive Charge Pump)
For lowest output voltage ripple, low-ESR ceramic capacitors are recommended. The actual value is not critical
and values in the range 1 µF to 10 µF are suitable for most applications. Larger capacitors provide better
performance in applications where large load transient currents are present.
A flying capacitor in the range 100 nF to 1 µF is suitable for most applications. Larger values experience a
smaller voltage drop by the end of each switching cycle, and allow higher output voltages and/or currents to be
achieved. Smaller values tend to be physically smaller and a bit cheaper. For best performance, it is
recommended to include a resistor of a few ohms (2 Ω is a good value to start with) in series with the flying
capacitor to limit peak currents occurring at the instant of switching.
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Temperature Compensation (Positive Charge Pump)
The output voltage (VGH) of the positive charge pump controller is defined by two voltages and two temperatures,
as illustrated in Figure 31. The temperature compensation scheme is optimized for use with 10 kΩ NTC
thermistors.
Positive Charge Pump
Output Voltage
VGH(COLD)
VGH(HOT)
T1
T2
Temperature
Figure 31. Positive Charge Pump Temperature Compensation
The error amplifier's non-inverting input, which is the reference voltage for VGH, is derived from the FBPH and
RNTC pins. A higher reference voltage generates a higher VGH.
VGH(COLD) is determined by the resistor connected to the FBPH and FBP pins:
æ
R ö
VGH(COLD) = IFBPH ´ R10 ´ ç 1 + 15 ÷
R16 ø
è
(9)
VGH(HOT) is set by an internal clamping circuit and the resistor divider connected to the FBP pin:
æ
R ö
VGH(HOT) = VREF × ç1 + 15 ÷
R16 ø
è
(10)
The NTC network connected to the RNTC pin defines the temperatures T1 and T2.
Temperature compensation can be disabled by connecting a 10 kΩ resistor between the FBPH pin and AGND
and by tying the RNTC pin directly to AGND, in which case Equation 10 should be used to calculate VGH.
Suppose a circuit with the following characteristics is required:
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Example
A Microsoft Excel spreadsheet is available that allows easy calculation of temperature compensation
components and eliminates the need for the following expressions to be calculated manually. Contact the
factory to receive a free copy.
Suppose a circuit with the following characteristics is required:
T1 = 40°C
T2 = 60°C
VGH(COLD) = 28 V
VGH(HOT) = 20 V
Space
1. The first step is to calculate the resistance of the NTC at temperatures T1 and T2
At temperature T1, RNTC(T1) = 5302 Ω
At temperature T2, RNTC(T2) = 2486 Ω
Space
2. The next step is to calculate the feedback resistors R15 and R16 as follows:
VGH(HOT)
R15
-1
=
R16
VREF
R15
R16
=
20V
- 1 = 15.13 V
1.24V
(11)
Suitable standard values from the E96 series would be R15 = 19.6 kΩ and R16 = 1.3 kΩ. With these values,
the current through the feedback divider is of the order of 1mA and the nominal output voltage at high
temperatures is:
æR
ö
VGH(HOT) = VREF ´ ç 15 + 1 ÷
è R16
ø
æ 19.6 kΩ
ö
VGH(HOT) = 1.24 V ´ ç
+ 1÷ = 19.94 V
è 1.3 kΩ
ø
(12)
Space
3. Now calculate VFBPH as follows:
æ
ö
R16
VFBPH = VGH(HOT) × ç
÷
è R15 + R16 ø
1.3 kΩ
æ
ö
VFBPH = 28 V × ç
÷ = 1.742 V
è 19.6 kΩ + 1.3 kΩ ø
(13)
Space
The value of R10 required to generate VFBPH can now be calculated, as follows:
V
R10 = FBPH
IFBPH
R10 =
1.742 V
= 8.71 kΩ
200 μA
(14)
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Two 17.4 kΩ resistors in parallel would be suitable for R10, giving an output voltage at low temperatures
given by:
æR
ö
VGH(COLD) = IFBPH ´ R10 ´ ç 15 + 1÷
è R16
ø
VGH(COLD) = 200 μA ´
17.4 kΩ
æ 19.6 kΩ
ö
´ ç
+ 1÷ = 28.0 V
2
1.3
kΩ
è
ø
(15)
Space
The value of R12 can be calculated by solving a standard quadratic equation:
b2 - 4 ´ a ´ c
2 ´ a
-b ±
R12 =
(16)
Where:
(
)
a=
ISET
´ RNTC(T1) - RNTC(T2) - 1
VFBPH - VREF
a=
200 μA
´ (5.30 kΩ - 2.49 kΩ ) - 1 = 0.124
1.74 V - 1.24 V
Space
b = RT1 + RT2
b = 5.30 kΩ + 2.49 kΩ = 7.79 kΩ
Space
c = RT1 ´ RT2
c = 5.30 kΩ ´ 2.49 kΩ = 13.2 ´ 10 6 Ω2
Space
Using the coefficients a, b, and c we can solve for R12:
R12 =
7.79 kΩ +
7.79 kΩ 2 + 4 × 0.124 × 13.2 × 10 6Ω 2
2 × 0.124
R12 = 64.5 kΩ
A standard value of 64.9 kΩ can be used for R12.
Space
4. The final step is to calculate the value of R11 using Equation 10.
R11 =
R11 =
VREF
IRNTC
-
R T2 ´ R12
R T2 + R12
1.24 V
200 μA
2.49 kΩ × 64.9 kΩ
-
2.49 kΩ + 64.9 kΩ
= 3.8 kΩ
(17)
A standard value of 3.83 kΩ can be used for R12.
Figure 32 shows the temperature dependence of VGH resulting from the above calculated values.
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30
28
VGH - V
26
24
22
20
18
16
0
10
20
30
40
50
60
Temperature - °C
70
80
90
100
Figure 32. Temperature Compensated VGH
Short-Circuit Protection (Positive Charge Pump)
During start-up, the positive charge pump limits the current available from VGH until VFBP > 124 mV. If VFBP is still
less than 124 mV after 15 ms, the boost converter, and positive and negative charge pumps are disabled. Either
VIN or EN must be cycled to recover normal operation.
During normal operation (i.e. once the positive charge pump has reached its power good threshold) short circuits
are detected if VFBP falls below 0.34 V (approx. 30% of VREF). If this happens the boost converter and positive
and negative charge pumps are disabled. Either VIN or EN must be cycled to recover normal operation.
Undervoltage Protection (Positive Charge Pump)
During operation, if the output of the positive charge pump falls below its power good threshold for longer than
55ms, the TPS65155 will detect an undervoltage condition and turn itself off. VIN or EN must be cycled to recover
normal operation.
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Negative Charge Pump Controller
The negative charge pump controller uses an external NPN transistor to regulate an external charge pump
circuit. The controller is optimized for transistors having a DC gain (hFE) in the range 100 to 300. Regulation of
the charge pump's output voltage is achieved by using the external transistor as a controlled current source
whose output current depends on the voltage applied to the FBN pin. The higher the transistor's output current,
the higher (i.e., more negative) the charge pump's output voltage.
93 mV
-
UVP (Normal)
+
850 mV
+
794 mV
VAVDD
55 ms
Timer
-
SCP (Normal)
Control
Logic
Short-Circuit
Mode
300 μA
SW
Normal
Mode
SCP (Start-Up)
2.5 mA
+
FBN
R8
+
-
C10
D7
Error
Amplifier
VREF
C11
D6
DRVN
VGL
Q2
C13
R22
R14
R13
Figure 33. Negative Charge Pump Internal Block Diagram
Setting the Output Voltage (Negative Charge Pump)
The negative charge pump's output voltage is programmed by a resistor divider according to Equation 18.
R
VGL = - VREF ´ 13
R14
(18)
Rearranging Equation 18, the values of R13 and R14 can be easily calculated.
VGL
R13 = R14 ´
VREF
(19)
Because of its limited output current capability, it is recommended to keep the current drawn from the VREF pin
below 250 µA to achieve best accuracy. A good approach is to use a value of at least 5.1 kΩ for the lower
resistor (R14) and then select the upper resistor (R13) to set the desired output voltage. If a minimum charge
pump load is desired (e.g. to improve regulation at very low load currents), it is best to add an additional resistor
between VGL and GND, rather than reduce the values of R13 and R14.
Note that the maximum voltage in an application is determined by the boost converter's output voltage and the
voltage drop across the diodes and NPN transistor. For a typical application in which the negative charge pump
is configured as a voltage inverter, the maximum (i.e., most negative) output voltage is given by Equation 20.
VGL(MAX) = - VAVDD + (2 ´ VF ) + VCE
(20)
Where VF is the forward voltage of each diode and VCE is the collector-emitter voltage of the NPN transistor
(recommended to be at least 1 V, to avoid transistor saturation).
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Selecting the NPN Transistor (Negative Charge Pump)
The NPN transistor used to regulate VGL should have a DC gain (hFE) of at least 100 when its collector current is
equal to the charge pump's output current. The transistor should also be able to withstand voltages up to VAVDD
across its collector-emitter (VCE).
The power dissipated in the transistor is given by Equation 21. The transistor must be able to dissipate this
power without its junction becoming too hot. Note that the ability to dissipate power depends heavily on adequate
PCB thermal design.
PQ = éë V AVDD - (2 ´ VF ) - VGL ûù ´ IGL
(21)
Where IGL is the mean (not RMS) output current drawn from the charge pump.
Selecting the Diodes (Negative Charge Pump)
Small-signal diodes can be used for most low current applications (<50 mA) and higher rated diodes for higher
power applications. The average current through the diode is equal to the output current, so that the power
dissipated in the diode is given by Equation 22.
PD = IGL ´ VF
(22)
The peak current through the diode occurs during start-up and for a few cycles may be as high as a few amps.
However, this condition typically lasts for <1 ms and can be tolerated by many diodes whose repetitive current
rating is much lower. The diodes' reverse voltage rating should be equal to at least 2×VAVDD.
Table 4. Negative Charge Pump Diode Selection
PART NUMBER
IAVG
IPK
VR
VF
COMPONENT SUPPLIER
BAV99W
150 mA
1 A for 1 ms
75 V
1 V at 50 mA
NXP
BAT54S
200 mA
600 mA for 1 s
30 V
0.8 V at 100 mA
Fairchild Semiconductor
MBR0540
500 mA
5.5 A for 8 ms
40 V
0.51 at 500 mA
Fairchild Semiconductor
Selecting the Capacitors (Negative Charge Pump)
For lowest output voltage ripple, low-ESR ceramic capacitors are recommended. The actual value is not critical
and 1 µF to 10 µF is suitable for most applications. Larger capacitors provide better performance in applications
where large load transient currents are present.
A flying capacitor in the range 100 nF to 1 µF is suitable for most applications. Larger values experience a
smaller voltage drop by the end of each switching cycle, and allow higher output voltages and/or currents to be
achieved. Smaller values tend to be physically smaller and a bit cheaper.
A collector capacitor in the range 100 nF to 1 µF is suitable for most applications. Larger values are more
suitable for high current applications but can affect stability if they are too big.
Short-Circuit Protection (Negative Charge Pump)
During start-up the negative charge pump limits the current available from VGL until VFBN is less than 794 mV. If
VFBN is still higher than 794 mV after ≈ 20 ms (1), the boost converter, and positive and negative charge pumps
are disabled. Either VIN or EN must be cycled to recover normal operation.
During normal operation (i.e., once the negative charge pump has reached its power good threshold), short
circuits are detected if VFBN rises above 850 mV. If this happens, the boost converter, and positive and negative
charge pumps are disabled. Either VIN or EN must be cycled to recover normal operation.
Undervoltage Protection (Negative Charge Pump)
During operation, if the output of the negative charge pump falls below its power good threshold for longer than
55ms, the TPS65155 will detect an undervoltage condition and turn itself off. VIN or EN must be cycled to recover
normal operation.
(1)
Actually 10ms after the boost converter's power good.
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Reset Generator (XAO)
The TPS65155 generates an open-drain reset signal that can be used to disable the T-CON during power-down.
The XAOsignal is pulled low when VDET < VREF and is high impedance when VDET > VREF (+ hysteresis). The
reset generator is not disabled when VIN falls below the UVLO threshold, and continues to function down to very
low values of VIN.
I2C Interface
The TPS65155 has an I2C serial interface for internal test purpose. Both the SCL and SDA need be pulled to
VIN.
Level Shifters
The TPS65155 contains six level shifter channels (see Figure 34). Each channel features a logic-level input
stage and a high-level output stage powered from VGH and VGL. The output stages are capable of generating
high peak currents to drive the capacitive loads typically present in an LCD panel. Because the capacitive load
typically connected to the STV and RESET channels is relatively small, the peak current available from these two
channels is slightly lower than that available from the CLK channels.
During power-up, the level shifter outputs track VGL. During power-down, the level shifter outputs track VGH.
Power-up and power-down conditions are determined by the VDET threshold of the panel discharge function,
which also controls the level shifter channels during power-up and power-down.
VGH
Level
Shifter
CLKIN1 to CLKIN4
VGL
VGH
STRONG
NORMAL
Level
Shifter
STVIN, RESETIN
CLKOUT1 to CLKOUT4
STVOUT, RESETOUT
VGL
Figure 34. Level Shifter Block Diagram
Power Supply Sequencing (Boost and Charge Pumps)
•
•
•
•
When VIN < VUVLO, all functions are disabled. (2)
When VIN > VUVLO, all functions are disabled if EN is low.
When VIN > VUVLO and EN goes high, the boost converter and negative charge pump are enabled first. When
the output of the boost converter reaches its power good threshold, the positive charge pump is enabled.
If EN goes low, all functions are disabled.
Power Supply Sequencing (Level Shifters)
•
•
•
(2)
(3)
26
During power-up, when VDET is below its input threshold, the level shifter outputs track VGH. (3)
During normal operation, when VDET is above its input threshold, the level shifter outputs follow their inputs.
During power-down, when VDET falls below its input threshold, the level shifter outputs track VGH.
The level shifter discharge function continues to function for as long as there is sufficient operating voltage on VGH and VGL
The level shifter discharge function continues to function for as long as there is sufficient operating voltage on VGH and VGL
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Power Supply Sequencing (XAO)
•
•
•
During power-up, when VDET is still below its input threshold, XAOis pulled low.
During normal operation, when VDET is above its input threshold, XAO is high impedance.
During power-down, when VDET falls below its input threshold, XAO is pulled low.
VIN
VIN < VUVLO
VIN < VDET
VIN > VUVLO
VIN > VDET
EN
VAVDD > VPG
VAVDD
Minimum operating VGL (≈-2V)
VGL
VGH
VGH > VUVLO (≈8V)
VGH < VUVLO (≈3V)
Tracks VGH
Level Shifter
Outputs
Tracks VGL
Figure 35. Power Supply Sequencing Using EN Pin, VDET < VUVLO
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VIN
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VIN > VDET
VIN > VUVLO
VIN < VDET
VIN < VUVLO
EN
VAVDD > VPG
VAVDD
Minimum operating VGL (≈-2V)
VGL
VGH
VGH > VUVLO (≈8V)
VGH > VUVLO (≈3V)
Tracks VGH
Level Shifter
Outputs
Tracks VGL
Figure 36. Power Supply Sequencing Using EN Pin, VDET > VUVLO
VIN > VUVLO
VIN > VDET
VIN
VIN < VUVLO
VIN < VDET
VAVDD > VPG
VAVDD
Min. Operating VGL (≈-2V)
VGL
VGH
VGH > VUVLO (≈8V)
VGH < VUVLO (≈3V)
Tracks VGH
Level Shifter
Outputs
Tracks VGL
Figure 37. Power Supply Sequencing with EN Pin Tied to VIN, VDET < VUVLO
28
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VIN > VDET
VIN > VUVLO
VIN
VIN < VDET
VIN < VUVLO
VAVDD < VPG
VAVDD
Minimum operating VGL (≈-2V)
VGL
VGH
VGH > VUVLO (≈8V)
VGH < VUVLO (≈3V)
Tracks VGH
Level Shifter
Outputs
Tracks VGL
Figure 38. Power Supply Sequencing with EN Pin Tied to VIN, VDET > VUVLO
Undervoltage Lockout
The TPS65155 features an undervoltage lockout (UVLO) function that disables the LCD bias functions if the
supply voltage (VIN) is below the minimum needed for correct operation (VUVLO).
Thermal Shutdown
A thermal shutdown function automatically disables all LCD bias functions if the device’s junction temperature
exceeds the safe maximum. The device automatically starts operating again once it has cooled down.
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APPLICATION INFORMATION
4u7
VIN
10u
VAVDD
16.1V
40u
22n
47k
12k
SW
AVDD
VIN
FB
SS
2R2
COMP
3n3
SW
1k
470n
FREQ
VAVDD
7k32
RNTC
DRVP
3.3V
6k98
28.3 V @ T < –10°C
24 V @ T > +10°C
VGH
10k
XAO
1u
100k
1k05
FBPH
22k
XAO
FBP
SW
10u
2R2
1k2
470n
DRVN
100k
EN
VIN
100n
SCL
VGL
SDA
–10V
10k
10u
VDET
80k6
FBN
10k
10k
VREF
100n
STVOUT
STVIN
RESETIN
RESETOUT
CLKIN1
CLKOUT1
CLKIN2
CLKOUT2
CLKIN3
CLKOUT3
CLKIN4
CLKOUT4
GND
PGND
AGND
LGND
Figure 39. Typical Application Circuit Using Positive Charge Pump in ×2 Configuration
30
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4u7
VAVDD
VIN
10u
10u
22n
47k
40u
SW
AVDD
VIN
SW
FB
SS
2R2
COMP
3n3
1k
470n
470n
FREQ
VIN
7k32
FBPH
RNTC
DRVP
3.3V
6k98
22k
XAO
1u
28.3 V @ T < –10°C
24 V @ T > +10°C
VGH
10k
XAO
1u
100k
1k05
SW
10u
FBP
2R2
1k2
470n
DRVN
100k
EN
VIN
100n
SCL
VGL
SDA
–10V
10k
10u
VDET
80k6
FBN
10k
10k
VREF
100n
STVOUT
STVIN
RESETIN
RESETOUT
CLKIN1
CLKOUT1
CLKIN2
CLKOUT2
CLKIN3
CLKOUT3
CLKIN4
CLKOUT4
GND
PGND
AGND
LGND
Figure 40. Typical Application Circuit Using Positive Charge Pump in ×2.5 Configuration
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PACKAGE OPTION ADDENDUM
www.ti.com
11-Jun-2012
PACKAGING INFORMATION
Orderable Device
TPS65155RKPR
Status
(1)
ACTIVE
Package Type Package
Drawing
VQFN
RKP
Pins
Package Qty
40
1
Eco Plan
(2)
Green (RoHS
& no Sb/Br)
Lead/
Ball Finish
MSL Peak Temp
(3)
Samples
(Requires Login)
CU NIPDAU Level-2-260C-1 YEAR
(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.
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 1
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