TEXAS INSTRUMENTS tps5103 Technical data

D
Step-Down DC-DC Converter
D
Three Operation-Mode – Heavy Load:
– Fixed Frequency PWM – Hysteretic (User Selctable)
– Light Load:
– Skip Mode
D
4.5 V to 25 V Input Voltage Range
D
Adjustable Output Voltage Down to 1.2 V
D
95% Efficiency
D
Stand-By Control
D
Over Current Protection
D
UVLO for Internal 5 V Regulation
D
Low Standby Current . . . 0.5 mA Typical
D
TA = –40°C to 85°C
description
TPS5103
MULTIPLE MODE SYNCHRONOUS DC/DC CONTROLLER
SLVS240 – SEPTEMBER 1999
DB PACKAGE
(TOP VIEW)
1
20
SOFTSTART
INV
FB C R
GND
REF
COMP
PWMSKIP
STBY
2 3 4
5
6 7 8 9 10
LH
19
OUT_u
18
LL
17
OUT_d
16
OUTGND
15
TRIP
14
VCC_SENSE
13
VCC
12
VREF5
11
VREG5V_IN
The TPS5103 is a synchronous buck dc/dc controller, designed for notebook PC system power . The controller has three user-selectable operation modes available; hysteretic mode, fixed frequency PWM control, or SKIP control.
In high current applications, where fast transient response is advantageous for reducing bulk capacitance, the hysteretic mode is selected by connecting the Rt pin to Vref5. Selecting the PWM/SKIP modes for less demanding transient applications is ideal for conserving notebook battery life under light load conditions. The device includes high-side and low-side MOSFET drivers capable of driving low Rds (on) N–channel MOSFET s.
The user-selectable overcurrent protection (OCP) threshold is set by an external TRIP pin resister in order to protect the system. The TPS5103 is configured so that a current sense resistor is not required, improving the operating efficiency.
L1
C4
C5
OUTPUT
+
R2
C1
C2
R1
1 2 3 4 5 6 7 8 9
10
TPS5103
SOFTSTART INV FB CT RT GND REF COMP PWM/SKIP STBY
U1
OUTU
OUTD
OUTGND
VCCSENSE
VREF5
VREG5V_IN
LH
LL
TRIP
VCC
5 V
D1
20 19 18 17 16 15 14 13 12 11
C3
R3
R4
Q1
Q2
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.
TI is a trademark of Texas Instruments Incorporated.
PRODUCT PREVIEW information concerns products in the formative or design phase of development. Characteristic data and other specifications are design goals. Texas Instruments reserves the right to change or discontinue these products without notice.
POST OFFICE BOX 655303 DALLAS, TEXAS 75265
Figure 1. Typical Design
Copyright 1999, Texas Instruments Incorporated
1
TPS5103
°C
MULTIPLE MODE SYNCHRONOUS DC/DC CONTROLLER
SLVS240 – SEPTEMBER 1999
functional block diagram
SOFT START
FB
INV
PWMSKIP
C R
Comp
1.185 V
Soft Start
1.185 V
_ +
_ +
Error Amp
PWM Comp.
_ +
One Shot ON
_ +
OSC
_ +
Disable
_ +
UVLO
LH
OUT_u LL
OUT_d OUTGND
TRIP
VCC_SENSE
VREF5
GND
V
CC
STBY
REF
1.185 V
°
–40 °C to 85
VREF
AVAILABLE OPTIONS
A
°
SSOP(DB) EVM
TPS5103IDB TPS5103EVM–136
TPS5103IDBR
PACKAGE
_ +
VREG5V_IN
2
POST OFFICE BOX 655303 DALLAS, TEXAS 75265
I/O
DESCRIPTION
MULTIPLE MODE SYNCHRONOUS DC/DC CONTROLLER
Terminal Functions
TERMINAL
NAME NO.
COMP 8 I Comparator input for voltage monitor C
FB 3 O Feedback output of error amp GND 6 Control GND INV 2 I Inverting input of both error amp and hysteretic comparator LH 20 I/O Bootstrap. Connect 1 µF low-ESR capacitor from LH to LL.
LL 18 I/O OUT_d 17 I/O Gate-drive output for low-side power switching FET s
OUTGND 16 Ground for FET drivers OUT_u 19 O Gate-drive output for high-side power switching FET s
PWMSKIP 9 I
REF 7 O 1.185-V reference voltage output R
SOFTSTAR T 1 I External capacitor from SOFTST ART to GND for soft start control STBY 10 I Standby control TRIP 15 I External resistor connection for output current control V
CC
VCC_SENSE 14 I Supply voltage sense for current protection VREF5 12 O 5-V-internal regulator output VREG5V_IN 11 I External 5-V input (input voltage range = 4.5 V to 25 V)
4 I/O
5 I/O External resistor connection for adjusting the triangle oscillator.
13 I Supply voltage input
External capacitor from CT to GND for adjusting the triangle oscillator and decreasing the current limiting voltage
Bootstrap low. High side gate driving return and output current protection. Connect to the junction of the high side and low side FETs for floating drive configuration.
PWM/SKIP mode select L:PWM mode H:SKIP mode
TPS5103
SLVS240 – SEPTEMBER 1999
POST OFFICE BOX 655303 DALLAS, TEXAS 75265
3
TPS5103 MULTIPLE MODE SYNCHRONOUS DC/DC CONTROLLER
SLVS240 – SEPTEMBER 1999
detailed description
REF
The reference voltage is used for the output voltage setting and the voltage protection(COMP). The tolerance is 1.5% typically.
VREF5
An internal linear voltage regulator is used for the high-side driver bootstrap voltage. Since the input voltage range is from 4.5 V to 25 V, this voltage offers a fixed voltage for the bootstrap voltage so that the design for the bootstrap is much easier. The tolerance is 6%.
hysteretic comparator
The hysteretic comparator is used to regulate the output voltage of the synchronous-buck converter. The hysteresis is set internally and is typically 9.7 mV. The total delay time from the comparator input to the driver output is typically 400 ns for going both high and low.
error amplifier
The error amplifier is used to sense the output voltage of the synchronous buck converter. The negative input of the error amplifier is connected to the Vref voltage(1.185 V) with a resistive divider network. The output of the error amplifier is brought out to the FB terminal to be used for loop gain compensation.
low-side driver
The low-side driver is designed to drive low-Rds(on) n-channel MOSFETs. The maximum drive voltage is 5 V from VREF5. The current rating of driver is typically 1.2 A at sink current, –1.5 A at source current.
high-side driver
The high-side driver is designed to drive low-Rds(on) n-channel MOSFETs. The current rating of the driver is
1.2 A at sink current, –1.7 A at source current. When configured as a floating driver, the bias voltage to the driver is developed from the VREF5, limiting the maximum drive voltage between OUT_u and LL to 5 V . The maximum voltage that can be applied between LH and OUTGND is 30 V.
driver deadtime control
The deadtime control prevents shoot-through current from flowing through the main power FETs. During
switching transitions the deadtime from the low-side-driver-off to the high-side-driver-on is 90 ns, and 110 ns from high-side-driver-off to low-side-driver-on.
COMP
COMP is designed for use with a regulation output monitor. COMP also functions as an internal comparator used for any voltage protection such as the input under voltage protection. If the input voltage is lower than the setpoint, the comparator turns off and prevents external parts from damage. The investing terminal of the comparator is internally connected to REF(1.185 V).
current protection
Current protection is achieved by sensing the high-side power MOSFET drain-to-source voltage drop during on-time through VCC_SENSE and LL terminals. An external resistor between Vin and TRIP terminal with the internal current source connected to the current comparator negative input adjusts the current limit. The typical internal current source value is 15 µA in PWM mode, 5 µA in SKIP mode. When the voltage on the positive terminal is lower than the negative terminal, the current comparator turns on the trigger, and then activates the oscillator. This oscillator repeatedly reset the trigger until the over current condition is removed. The capacitor on the C
terminal can be open or added to adjust the reset frequency.
T
deadtime control actively controls the turnon time of the MOSFET drivers. The typical
4
POST OFFICE BOX 655303 DALLAS, TEXAS 75265
MULTIPLE MODE SYNCHRONOUS DC/DC CONTROLLER
SLVS240 – SEPTEMBER 1999
detailed description (continued)
softstart
SOFTST ART sets the sequencing of the output for any possibility. The capacitor value for a start-up time can be calculated by the following equation: C = 2xT (uF) where C is the external capacitor value, T is the required start-up time in (ms).
standby
This controller can be switched into standby mode by grounding the STBY terminal. When it is in standby mode, the quiescent current is less than 1.0 uA.
UVLO
The under-voltage-lock-out (ULVO) threshold is approximately 3.8 V. The typical hysteresis is 55 mV.
5-V Switch
5-V Switch if the internal 5-V switch senses a 5-V input from REG5V terminal, the internal 5-V linear regulator will be disconnected from the MOSFET drivers. The external 5 V will be used for both the low-side driver and the high-side bootstrap, thus increasing the efficiency.
PWM/SKIP switch
TPS5103
The PWM/SKIP switch selects the output operating mode. This controller has three operational modes, PWM, SKIP, and Hysteretic. The PWM and SKIP mode control should be used for slower transient applications.
oscillator
The oscillator gives a triangle wave by connecting an external resistor to the R
terminal and an external
T
capacitor to the CT terminal. The voltage amplitude is 0.43 V ~ 1.17 V. This wave is connected to the non­inverting input of the PWM comparator.
Comparison Table Between PWM Mode and Hysteretic Mode
MODE PWM HYSTERETIC
Frequency Fixed Not Fixed Transient Response Normal Very fast Feed back compensation Need Needless
POST OFFICE BOX 655303 DALLAS, TEXAS 75265
5
TPS5103
VIInput voltage
V
MULTIPLE MODE SYNCHRONOUS DC/DC CONTROLLER
SLVS240 – SEPTEMBER 1999
absolute maximum ratings over operating free-air temperature (unless otherwise noted)
Supply voltage, VCC (see Note 1) –0.3 V to 27 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Input voltage, VI, INV, CT, RT, PWM/SKIP, SOFTSTART, COMP –0.3 V to 7 V. . . . . . . . . . . . . . . . . . . . . . . . . .
Input voltage, VREG5V_IN –0.3 V to 6 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Input voltage, STBY –0.3 V to 15 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Input voltage, TRIP, VCC_SENSE –0.3 V to 27 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Output current, I
3 A. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
O
Low level output voltage, VOL –0.3 V to 27 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
High level output voltage, V Reference voltage, V
–0.3 V to 3 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
ref
–0.3 V to 32 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
OH
Operating free-air temperature range, TA –40°C to 85°C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Operating virtual junction temperature range, TJ –125°C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Storage temperature range, T
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.
NOTES: 1. All voltage values are with respect to the network ground terminal.
2. See Dissipation Rating Table for free-air temperature range above 25°C.
PACKAGE
DB 801 mW 6.408mW/ °C 416 mW
–55°C to 150°C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
stg
DISSIPATION RATING TABLE
TA 25°C
POWER RATING
DERATING FACTOR
ABOVE TA = 25°C
TA = 85°C
POWER RATING
recommended operating conditions
MIN NOM MAX UNIT
V
CC
R
C
f Frequency 200 kHz T
A
Not a JEDEC symbol.
Supply voltage 4.5 25 V
INV, CT, RT, COMP, PWM_SKIP, SOFTSTART 6
p
‡ ‡
Oscillator frequency
Operating temperature range –40 85 °C
VREG5V_IN 5.5 STBY 12 TRIP, VCC_SENCE 25 Timing register 82 k Timing capacitor 100 pF
6
POST OFFICE BOX 655303 DALLAS, TEXAS 75265
V
Reference voltage
V
Frequency change
V
High-level output voltage
V
V
Low-level output voltage
V
V
High-level input voltage
V
V
Low-level input voltage
V
TPS5103
MULTIPLE MODE SYNCHRONOUS DC/DC CONTROLLER
SLVS240 – SEPTEMBER 1999
electrical characteristics over recommended operating free-air temperature range, VCC = 7 V (unless otherwise noted)
reference voltage
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
ref
Regin Line regulation Regl Load regulation
Not a JEDEC symbol.
TA = 25°C, I
= 50 µA
I
vref
VCC = 4.5 V to 25 V, I = 50 µA 0.2 12 mV I = 1 µA to 1 mA 0.5 10 mV
oscillator
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
f Frequency PWM mode 500 kHz R
fdv fdt
HL
LL
Not a JEDEC symbol.
The output voltages of oscillator (f = 200 kHz) are ensured by design.
Timing resistor 47 k
VCC = 4.5 V to 25 V 0.1% TA = –40°C to 85°C 2%
p
p
DC includes internal comparator error 1 1.1 1.2 f = 200 kHz, includes internal comparator error 1.17 DC includes internal comparator error 0.4 0.5 0.6 f = 200 kHz, includes internal comparator error 0.43
= 50 µA 1.167 1.185 1.203
vref
1.155 1.215
error amp
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
V Input offset voltage TA = 25°C 2 10 mV Av Open-loop voltage gain GB Unity-gain bandwidth I
O
I
S
Not a JEDEC symbol.
Output sink current VO = 0.4 V 30 45 µA Output source current VO = 1 V 300 µA
hysteresis comparator
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
V
hsy
Vp-VSOffset voltage 2 mV I Bias current 10 pA t
PHL
t
PLH
§
The numbers in the table include the driver delay. All numbers are ensured by design.
Hysteresis window Hysteretic mode 6 9.7 13 mV
Propagation delay from INV to OUT_U TTL input signal 230 ns
50 dB
0.8 MHz
§
10 mV overdrive on hysteresis band signal 400 ns
control
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
IHA
ILA
p
p
STBY 2.5 PWM_SKIP 2 STBY 0.5 PWM_SKIP 0.5
POST OFFICE BOX 655303 DALLAS, TEXAS 75265
7
TPS5103
Threshold voltage
V
Threshold voltage
V
I
TRIP terminal current
A
MULTIPLE MODE SYNCHRONOUS DC/DC CONTROLLER
SLVS240 – SEPTEMBER 1999
electrical characteristics over recommended operating free-air temperature range, VCC = 7 V (unless otherwise noted) (continued)
5-V regulator
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
V
O
Regin Line regulation Regl Load regulation I
OS
Not a JEDEC symbol.
5-V switch
V
IT(high)
V
IT(low)
V
hsy
Not a JEDEC symbol.
UVLO
V
IT(high)
V
IT(low)
V
hys
Not a JEDEC symbol.
Output voltage I = 10 mA 4.7 5.3 V
Short-circuit output current V
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
Hysteresis) 50 150 250 mV
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
Hysteresis 10 150 mV
VCC = 5.5 V to 25 V, I = 10 mA 20 mV I = 1 mA to 10 mA, VCC = 5.5 V 40 mV
= 0 V 70 mA
ref
4.2 4.9
4.1 4.8
3.6 4.2
3.5 4.1
output
I
O
I
S
I
O
I
S
t
r
t
f
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
OUT_u sink curent VO = 3 V 0.5 1.2 A OUT_u source current VO = 2 V –1 –1.7 A OUT_d sink current VO = 3 V 0.5 1.2 A OUT_d source current VO = 2 V –1 –1.5 A
PWM mode, VTRIP = 7 V 10 15 20 SKIP mode, VTRIP = 7 V 3 5 7 High side driver is GND referenced. Input: INV = 0 – 3V
Rise time
Fall time
tr/tf = 10 ns, CL = 2200 pF 28 CL = 3300 pF 39 High side driver is GND referenced. Input: INV = 0 – 3 V tr/tf = 10 ns, CL = 2200 pF 30 CL = 3300 pF 38
Frequency = 200 kHz
Frequency = 200 kHz
µ
ns
ns
8
POST OFFICE BOX 655303 DALLAS, TEXAS 75265
V
TPS5103
MULTIPLE MODE SYNCHRONOUS DC/DC CONTROLLER
SLVS240 – SEPTEMBER 1999
electrical characteristics over recommended operating free-air temperature range, VCC = 7 V (unless otherwise noted) (continued)
softstart
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
I
(CTRL)
V
IT(high)
V
IT(low)
Not a JEDEC symbol.
output voltage monitor
V
IT
driver deadtime section
DRVLH
DRVHL
whole device
I
CC
I Shutdown current STBY = 0 V 0.01 10 µA
Softstart current 1.9 2.5 3 µA
Threshold voltage (SKIP mode)
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
Threshold voltage 1.08 1.18 1.28 V
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
Low-side to high-side 90 ns High-side to low-side 110 ns
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
Supply current 0.5 1.2 mA
3.9
2.6
0.1 µF
5V
SOFTSTART INV FB
C
R
GND
VCC_SENSE
REF COMP PWM SKIP STBY
OUTGND
TRIP
VCC
VREF5
5V_IN
Figure 2. Test Circuit
LH OUT_u
LL
OUT_d
0.1 µF
7V
POST OFFICE BOX 655303 DALLAS, TEXAS 75265
9
TPS5103 MULTIPLE MODE SYNCHRONOUS DC/DC CONTROLLER
SLVS240 – SEPTEMBER 1999
TYPICAL CHARACTERISTICS
QUIESCENT CURRENT
JUNCTION TEMPERATURE
700
650
Aµ
600
550
500
450
– Quiescent Current –
400
CC
I
350
300
–40 –20 25
TJ – Junction Temperature – °C
DRIVE OUTPUT VOLTAGE
5.5 VCC = 7 V,
TJ = 25°C
5
vs
VCC = 25 V
VCC = 7 V
Figure 3
vs
DRIVE CURRENT
VCC = 4.5 V
85 125
QUIESCENT CURRENT
JUNCTION TEMPERATURE
50
45
Aµ
40 35
30
25
20
– Quiescent Current –
15
CCS
I
10
5 0
–40 –20 25
TJ – Junction Temperature – °C
DRIVE OUTPUT VOLTAGE
3
VCC = 7 V, TJ = 25°C
2.5
vs
VCC = 25 V
VCC = 7 V
VCC = 4.5 V
85 125
Figure 4
vs
DRIVE CURRENT
10
4.5
– Drive Output Voltage – VV
3.5
(OUT_u)
4
3
0.1 0.7
I
(OUT_source)
– Drive Source Current – A
Figure 5
2
1.5
1
– Drive Output Voltage – VV
(OUT_u)
0.5
1
POST OFFICE BOX 655303 DALLAS, TEXAS 75265
0
0.1 0.7
I
(OUT_sink)
– Drive Source Current – A
Figure 6
1
TPS5103
MULTIPLE MODE SYNCHRONOUS DC/DC CONTROLLER
SLVS240 – SEPTEMBER 1999
TYPICAL CHARACTERISTICS
– Drive Output Voltage – VV
(OUT_d)
1.125
DRIVE OUTPUT VOLTAGE
vs
DRIVE CURRENT
6
TJ = 25°C
5
4
3
2
1
0
0.1 0.7
I
(OUT_source)
– Drive Source Current – A
Figure 7
OSCILLATOR OUTPUT VOLTAGE
vs
JUNCTION TEMPERATURE
DRIVE OUTPUT VOLTAGE
vs
DRIVE CURRENT
4.5 TJ = 25°C
4
3.5
3
2.5
2
– Drive Output Voltage – VV
1.5
1
(OUT_d)
0.5
1
0
0.1 0.7
I
(OUT_sink)
– Drive Source Current – A
1
Figure 8
OSCILLATOR OUTPUT VOLTAGE
vs
JUNCTION TEMPERATURE
500
1.115
1.105
1.095
– Oscillator Output Voltage – V
1.085
(osch)
V
1.075
VCC = 4.5 V, VCC = 7 V, VCC = 25 V
–40 –20 25
TJ – Junction Temperature – °C
Figure 9
85 125
495
490
– Oscillator Output Voltage – V
485
(oscl)
V
480
VCC = 4.5 V, VCC = 7 V, VCC = 25 V
–40 –20 25
TJ – Junction Temperature – °C
Figure 10
85 125
POST OFFICE BOX 655303 DALLAS, TEXAS 75265
11
TPS5103 MULTIPLE MODE SYNCHRONOUS DC/DC CONTROLLER
SLVS240 – SEPTEMBER 1999
TYPICAL CHARACTERISTICS
ERROR AMPLIFIER INPUT OFFSET VOLTAGE
vs
JUNCTION TEMPERATURE
2.5
2
VCC = 4.5 V, VCC = 7 V,
1.5
VCC = 25 V
1
0.5
– Error Amplifier Input Offset Voltage – mV
io
V
0
–40 –20 25
TJ – Junction Temperature – °C
85 125
Figure 11
ERROR AMPLIFIER OUTPUT VOLTAGE
vs
JUNCTION TEMPERATURE
6.2
6
5.8
5.6
5.4
5.2
VCC = 4.5 V, VCC = 7 V, VCC = 25 V
ERROR AMPLIFIER OUTPUT VOLTAGE
vs
JUNCTION TEMPERATURE
2.5
2
VCC = 4.5 V, VCC = 7 V,
1.5
1
– Error Amplifier Output V oltage – mV
0.5
om+
V
0
VCC = 25 V
–40 –20 25
TJ – Junction Temperature – °C
85 125
Figure 12
HYSTERESIS COMPARATOR HYSTERESIS VOLTAGE
vs
JUNCTION TEMPERATURE
10.5 VCC = 7 V
10.25
10
9.75
4.8
– Error Amplifier Output V oltage – mV
om–
4.6
V
4.4
12
5
–40 –20 25
TJ – Junction Temperature – °C
Figure 13
9.5
9.25
– Hysteresis Comparator Hysteresis Voltage – mV
hys
9
85 125
POST OFFICE BOX 655303 DALLAS, TEXAS 75265
V
–40 –20 25 85 125
TJ – Junction Temperature – °C
Figure 14
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