SLVS223B − NOVEMBER 1999 − REVISED AUGUST 2002
D Floating Bootstrap or Ground-Reference
D
D
D
D
D
D
D
D
D
D
D
D
D PACKAGE
(TOP VIEW)
High-Side Driver
Adaptive Dead-Time Control
50-ns Max Rise/Fall Times With 3.3-nF Load
2.4-A Typical Output Current
4.5-V to 15-V Supply Voltage Range
TTL-Compatible Inputs
Internal Schottky Bootstrap Diode
SYNC Control for Synchronous or
Nonsynchronous Operation
CROWBAR for OVP, Protects Against
Faulted High-Side Power FETs
Low Supply Current....3 mA Typical
Ideal for High-Current Single or Multiphase
Power Supplies
−40°C to 125°C Operating Virtual Junction
Temperature Range
Available in SOIC and TSSOP PowerPAD
Packages
ENABLE
IN
CROWBAR
NC
SYNC
DT
PGND
1
2
3
4
5
6
7
14
13
12
11
10
9
8
BOOT
NC
HIGHDR
BOOTLO
LOWDR
NC
VCC
PWP PACKAGE
(TOP VIEW)
ENABLE
IN
CROWBAR
NC
SYNC
DT
PGND
1
14
2
13
3
12
Thermal
4 Pad 11
5
10
6
9
7
8
BOOT
NC
HIGHDR
BOOTLO
LOWDR
NC
VCC
NC − No internal connection
description
The TPS2834 and TPS2835 are MOSFET drivers for synchronous-buck power stages. These devices are ideal
for designing a high-performance power supply using switching controllers that do not include on-chip MOSFET
drivers. The drivers are designed to deliver minimum 2-A peak currents into large capacitive loads. The
high-side driver can be configured as ground-reference or as floating-bootstrap. An adaptive dead-time control
circuit eliminates shoot-through currents through the main power FETs during switching transitions, and
provides high efficiency for the buck regulator. The TPS2834 and TPS2835 have additional control functions:
ENABLE, SYNC, and CROWBAR. Both high-side and low-side drivers are off when ENABLE is low. The driver
is configured as a nonsynchronous-buck driver disabling the low-side driver when SYNC is low. The CROWBAR
function turns on the low-side power FET, overriding the IN signal, for overvoltage protection against faulted
high-side power FETs.
The TPS2834 has a noninverting input, while the TPS2835 has an inverting input. These drivers are available
in 14-terminal SOIC and thermally enhanced TSSOP PowerPAD packages and operate over a junction
temperature range of −40°C to 125°C.
Related Synchronous MOSFET Drivers
DEVICE NAME
ADDITIONAL FEATURES
INPUTS
TPS2830
TPS2831
Noninverted
ENABLE, SYNC, and CROWBAR
CMOS
W/O ENABLE, SYNC, and CROWBAR
CMOS
W/O ENABLE, SYNC, and CROWBAR
TTL
TPS2832
TPS2833
Noninverted
TPS2836
TPS2837
Inverted
Inverted
Noninverted
Inverted
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 Incorporated.
Copyright 2002, Texas Instruments Incorporated
!"#$% ! & '("") % $& ! *(+, '$% ! -$%).
"!-('%& '! !"# %! &*)' '$% ! & *)" %/) %)"#& ! )0$& &%"(#) %&
&%$ -$"- 1$""$ %2. "!-('% ! *"!')&& 3 -!)& !% )')&&$" ,2 ',(-)
%)&% 3 ! $,, *$"$#)%)"&.
POST OFFICE BOX 655303
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1
SLVS223B − NOVEMBER 1999 − REVISED AUGUST 2002
AVAILABLE OPTIONS
PACKAGED DEVICES
TJ
SOIC
(D)
− 40°C to 125°C
TSSOP
(PWP)
TPS2834D
TPS2835D
TPS2834PWP
TPS2835PWP
The D and PWP packages are available taped and reeled. Add R
suffix to device type (e.g., TPS2834DR)
functional block diagram
8
14
1 MΩ
(TPS2834 Only)
250 kΩ
2
12
11
VCC
BOOT
HIGHDR
BOOTLO
IN
VCC
(TPS2835 Only)
10
250 kΩ
7
6
DT
ENABLE
1
5
SYNC
CROWBAR
2
POST OFFICE BOX 655303
3
• DALLAS, TEXAS 75265
LOWDR
PGND
SLVS223B − NOVEMBER 1999 − REVISED AUGUST 2002
Terminal Functions
TERMINAL
NAME
NO.
I/O
DESCRIPTION
BOOT
14
I
Bootstrap terminal. A ceramic capacitor is connected between BOOT and BOOTLO to develop the floating
bootstrap voltage for the high-side MOSFET. The capacitor value is typically between 0.1 µF and 1 µF.
BOOTLO
11
O
This terminal connects to the junction of the high-side and low-side MOSFETs.
CROWBAR
3
I
CROWBAR can to be driven by an external OVP circuit to protect against a short across the high-side
MOSFET. If CROWBAR is driven low, the low-side driver will be turned on and the high-side driver will be
turned off, independent of the status of all other control terminals.
DT
6
I
Dead-time control terminal. Connect DT to the junction of the high-side and low-side MOSFETs.
ENABLE
1
I
If ENABLE is low, both drivers are off.
HIGHDR
12
O
Output drive for the high-side power MOSFET
IN
2
I
Input signal to the MOSFET drivers (noninverting input for the TPS2834; inverting input for the TPS2835).
10
O
Output drive for the low-side power MOSFET
LOWDR
NC
4, 9, 13
No internal connection
PGND
7
SYNC
5
I
Power ground. Connect to the FET power ground.
Synchronous rectifier enable terminal. If SYNC is low, the low-side driver is always off; If SYNC is high, the
low-side driver provides gate drive to the low-side MOSFET.
VCC
8
I
Input supply. Recommended that a 1-µF capacitor be connected from VCC to PGND.
detailed description
low-side driver
The low-side driver is designed to drive low rDS(on) N-channel MOSFETs. The current rating of the driver is 2 A,
source and sink.
high-side driver
The high-side driver is designed to drive low rDS(on) N-channel MOSFETs. The current rating of the driver is 2 A,
source and sink. The high-side driver can be configured as a GND-reference driver or as a floating bootstrap
driver. The internal bootstrap diode is a Schottky, for improved drive efficiency. The maximum voltage that can
be applied from BOOT to ground is 30 V.
dead-time (DT) control
Dead-time control prevents shoot-through current from flowing through the main power FETs during switching
transitions by controlling the turnon times of the MOSFET drivers. The high-side driver is not allowed to turn
on until the gate drive voltage to the low-side FET is low, and the low-side driver is not allowed to turn on until
the voltage at the junction of the power FETs (Vdrain) is low; the TTL-compatible DT terminal connects to the
junction of the power FETs.
ENABLE
The ENABLE terminal enables the drivers. When enable is low, the output drivers are low. ENABLE is a
TTL-compatible digital terminal.
IN
The IN terminal is a TTL-compatible digital terminal that is the input control signal for the drivers. The TPS2834
has a noninverting input; the TPS2835 has an inverting input.
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
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SLVS223B − NOVEMBER 1999 − REVISED AUGUST 2002
detailed description (continued)
SYNC
The SYNC terminal controls whether the drivers operate in synchronous or nonsynchronous mode. In
synchronous mode, the low-side FET is operated as a synchronous rectifier. In nonsynchronous mode, the
low-side FET is always off. SYNC is a TTL-compatible digital terminal.
CROWBAR
The CROWBAR terminal overrides the normal operation of the driver. When CROWBAR is low, the low-side
FET turns on to act as a clamp, protecting the output voltage of the dc/dc converter against overvoltages due
to a short across the high-side FET. VIN should be fused to protect the low-side FET. CROWBAR is a
TTL-compatible digital terminal.
absolute maximum ratings over operating free-air temperature (unless otherwise noted)†
Supply voltage range, VCC (see Note 1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −0.3 V to 16 V
Input voltage range: BOOT to PGND (high-side driver ON) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −0.3 V to 30 V
BOOTLO to PGND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −0.3 V to 16 V
BOOT to BOOTLO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −0.3 V to 16 V
ENABLE, SYNC, and CROWBAR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −0.3 V to 16 V
IN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −0.3 V to 16 V
DT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −0.3 V to 30 V
Continuous total power dissipation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . See Dissipation Rating Table
Operating virtual junction temperature range, TJ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −40°C to 125°C
Storage temperature range, Tstg . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −65°C to 150°C
Lead temperature soldering 1,6 mm (1/16 inch) from case for 10 seconds . . . . . . . . . . . . . . . . . . . . . . . 260°C
† 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.
NOTE 1: Unless otherwise specified, all voltages are with respect to PGND.
DISSIPATION RATING TABLE
DERATING FACTOR
PWP with solder‡
TA ≤ 25°C
2668
PWP without solder‡
1024
10.24 mW/°C
563
409
D
749
7.49 mW/°C
412
300
PACKAGE
26.68 mW/°C
TA = 70°C
1467
TA = 85°C
1067
JUNCTION-CASE THERMAL RESISTANCE TABLE
PWP
Junction-case thermal resistance
‡ Test Board Conditions:
1. Thickness: 0.062I
2. 3I × 3I (for packages 27 mm long)
4. 2-oz copper traces located on the top of the board (0.071 mm thick)
5. Copper areas located on the top and bottom of the PCB for soldering
6. Power and ground planes, 1-oz copper (0.036 mm thick)
7. Thermal vias, 0.33 mm diameter, 1.5 mm pitch
8. Thermal isolation of power plane
For more information, refer to TI technical brief literature number SLMA002.
4
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2.07 °C/W
SLVS223B − NOVEMBER 1999 − REVISED AUGUST 2002
recommended operating conditions
MIN
NOM
MAX
UNIT
Supply voltage, VCC
4.5
15
V
Input voltage
4.5
28
V
BOOT to PGND
electrical characteristics over recommended operating virtual junction temperature range,
VCC = 6.5 V, ENABLE = High, CL = 3.3 nF (unless otherwise noted)
supply current
PARAMETER
VCC
VCC
TEST CONDITIONS
Supply voltage range
MIN
TYP
4.5
Quiescent current
V(ENABLE) = LOW,
V(ENABLE) = HIGH,
VCC =15 V
VCC =15 V
V(ENABLE) = HIGH,
f(SWX) = 200 kHz,
C(HIGHDR) = 50 pF,
See Note 2
VCC =12 V,
BOOTLO grounded,
C(LOWDR) = 50 pF,
MAX
15
100
300
3
400
UNIT
V
µA
A
mA
NOTE 2: Ensured by design, not production tested.
POST OFFICE BOX 655303
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5
SLVS223B − NOVEMBER 1999 − REVISED AUGUST 2002
electrical characteristics over recommended operating virtual junction temperature range,
VCC = 6.5 V, ENABLE = High, CL = 3.3 nF (unless otherwise noted) (continued)
output drivers
PARAMETER
High-side sink (see Note 3)
Peak output
current
High-side source
(see Note 3)
Low-side sink (see Note 3)
Low-side source
(see Note 3)
TEST CONDITIONS
Duty cycle < 2%,
tpw < 100 µs
(see Note 2)
Duty cycle < 2%,
tpw < 100 µs
(see Note 2)
Duty cycle < 2%,
tpw < 100 µs
(see Note 2)
Duty cycle < 2%,
tpw < 100 µs
(see Note 2)
MIN
TYP
V(BOOT) – V(BOOTLO) = 4.5 V,
V(HIGHDR) = 4 V
0.7
1.1
V(BOOT) – V(BOOTLO) = 6.5 V,
V(HIGHDR) = 5 V
1.1
1.5
V(BOOT) – V(BOOTLO) = 12 V,
V(HIGHDR) = 10.5 V
2
2.4
V(BOOT) – V(BOOTLO) = 4.5 V,
V(HIGHDR) = 0.5V
1.2
1.4
V(BOOT) – V(BOOTLO) = 6.5 V,
V(HIGHDR) = 1.5 V
1.3
1.6
V(BOOT) – V(BOOTLO) = 12 V,
V(HIGHDR) = 1.5 V
2.3
2.7
1.3
1.8
2
2.5
VCC = 4.5 V, V(LOWDR) = 4 V
VCC = 6.5 V, V(LOWDR) = 5 V
VCC = 12 V, V(LOWDR) = 10.5 V
VCC = 4.5 V, VLOWDR)) = 0.5V
VCC = 6.5 V, V(LOWDR)) = 1.5 V
VCC = 12 V, V(LOWDR0) = 1.5 V
V(BOOT) – V(BOOTLO) = 4.5 V,
V(HIGHDR)= 0.5 V
High-side sink (see Note 3)
Output
resistance
High-side source (see Note 3)
V(BOOT) – V(BOOTLO) = 6.5 V,
V(HIGHDR) = 0.5 V
V(BOOT) – V(BOOTLO) = 12 V,
V(HIGHDR) = 0.5 V
V(BOOT) – V(BOOTLO) = 4.5 V,
V(HIGHDR) = 4 V
V(BOOT) – V(BOOTLO) = 6.5 V,
V(HIGHDR)= 6 V
V(BOOT) – V(BOOTLO) = 12 V,
V(HIGHDR) =11.5 V
V(DRV) = 4.5 V, V(LOWDR)= 0.5 V
Low-side sink (see Note 3)
Low-side source (see Note 3)
3
3.5
1.4
1.7
2
2.4
2.5
3
MAX
UNIT
A
A
A
A
5
5
Ω
5
75
75
Ω
75
9
V(DRV) = 6.5 V, V(LOWDR) = 0.5 V
V(DRV) = 12 V, V(LOWDR) = 0.5 V
7.5
V(DRV) = 4.5 V, V(LOWDR) = 4 V
V(DRV) = 6.5 V, V(LOWDR)= 6 V
75
Ω
6
75
Ω
V(DRV) = 12 V, V(LOWDR) = 11.5 V
75
NOTES: 2: Ensured by design, not production tested.
3. The pullup/pulldown circuits of the drivers are bipolar and MOSFET transistors in parallel. The peak output current rating is the
combined current from the bipolar and MOSFET transistors. The output resistance is the rDS(on) of the MOSFET transistor when
the voltage on the driver output is less than the saturation voltage of the bipolar transistor.
6
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
SLVS223B − NOVEMBER 1999 − REVISED AUGUST 2002
electrical characteristics over recommended operating virtual junction temperature range,
VCC = 6.5 V, ENABLE = High, CL = 3.3 nF (unless otherwise noted) (continued)
dead-time control
PARAMETER
VIH
VIL
High-level input voltage
VIH
VIL
High-level input voltage
Low-level input voltage
Low-level input voltage
TEST CONDITIONS
LOWDR
Over the VCC range (see Note 2)
DT
Over the VCC range
MIN
TYP
MAX
0.7VCC
1
2
UNIT
V
V
1
V
NOTE 2: Ensured by design, not production tested.
digital control terminals (IN, CROWBAR, SYNC, ENABLE)
PARAMETER
VIH
VIL
TEST CONDITIONS
High-level input voltage
MIN
TYP
MAX
2
V
Over the VCC range
Low-level input voltage
UNIT
1
V
switching characteristics over recommended operating virtual junction temperature range,
ENABLE = High, CL = 3.3 nF (unless otherwise noted)
PARAMETER
TEST CONDITIONS
HIGHDR output (see Note 2)
Rise time
LOWDR output (see Note 2)
HIGHDR output (see Note 2)
LOWDR output (see Note 2)
HIGHDR going low (excluding
dead time) (see Note 2)
Propagation delay time
Propagation delay time
Driver nonoverlap time
LOWDR going high (excluding
dead time) (see Note 2)
LOWDR going low (excluding
dead time) (see Note 2)
DT to LOWDR and LOWDR to
HIGHDR (see Note 2)
TYP
MAX
V(BOOTLO) = 0 V
V(BOOTLO) = 0 V
60
V(BOOT) = 12 V,
VCC = 4.5 V
V(BOOTLO) = 0 V
50
50
V(BOOT) = 4.5 V,
V(BOOT) = 6.5 V,
UNIT
ns
40
VCC = 6.5 V
VCC = 12 V
V(BOOT) = 12 V,
VCC = 4.5 V
Fall time
MIN
V(BOOT) = 4.5 V,
V(BOOT) = 6.5 V,
30
ns
30
V(BOOTLO) = 0 V
V(BOOTLO) = 0 V
V(BOOTLO) = 0 V
50
40
ns
40
40
VCC = 6.5 V
VCC = 12 V
30
ns
30
V(BOOT) = 4.5 V,
V(BOOT) = 6.5 V,
V(BOOTLO) = 0 V
V(BOOTLO) = 0 V
95
V(BOOT) = 12 V,
V(BOOT) = 4.5 V,
V(BOOTLO) = 0 V
V(BOOTLO) = 0 V
70
V(BOOT) = 6.5 V,
V(BOOTLO) = 0 V
70
V(BOOT) = 12 V,
VCC = 4.5 V
V(BOOTLO) = 0 V
60
80
ns
80
ns
80
VCC = 6.5 V
VCC = 12 V
70
ns
60
VCC = 4.5 V
VCC = 6.5 V
40
170
25
135
VCC = 12 V
15
85
ns
NOTE 2: Ensured by design, not production tested.
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SLVS223B − NOVEMBER 1999 − REVISED AUGUST 2002
TYPICAL CHARACTERISTICS
FALL TIME
vs
SUPPLY VOLTAGE
RISE TIME
vs
SUPPLY VOLTAGE
50
50
CL = 3.3 nF
TJ = 25°C
45
40
40
t f − Fall Time − ns
t r − Rise Time − ns
CL = 3.3 nF
TJ = 25°C
45
High Side
35
30
Low Side
25
35
High Side
30
25
20
20
15
15
10
Low Side
10
4
5
6
7
9 10 11 12 13
8
VCC − Supply Voltage − V
14 15
4
5
6
Figure 1
VCC = 6.5 V
CL = 3.3 nF
45
11
12 13
14 15
VCC = 6.5 V
CL = 3.3 nF
40
t f − Fall Time − ns
High Side
t r − Rise Time − ns
10
50
40
35
30
Low Side
25
High Side
35
30
25
Low Side
20
20
15
15
−25
0
25
50
75
100
125
10
−50
−25
0
25
Figure 3
Figure 4
POST OFFICE BOX 655303
50
75
TJ − Junction Temperature − °C
TJ − Junction Temperature − °C
8
9
FALL TIME
vs
JUNCTION TEMPERATURE
50
10
−50
8
Figure 2
RISE TIME
vs
JUNCTION TEMPERATURE
45
7
VCC − Supply Voltage − V
• DALLAS, TEXAS 75265
100
125
SLVS223B − NOVEMBER 1999 − REVISED AUGUST 2002
TYPICAL CHARACTERISTICS
HIGH-TO-LOW PROPAGATION DELAY TIME
vs
SUPPLY VOLTAGE, HIGH TO LOW LEVEL
150
t PHL − High-to-Low Propagation Delay Time − ns
t PLH − Low-to-High Propagation Delay Time − ns
LOW-TO-HIGH PROPAGATION DELAY TIME
vs
SUPPLY VOLTAGE, LOW TO HIGH LEVEL
CL = 3.3 nF
TJ = 25°C
140
130
120
110
100
90
80
70
60
Low Side
50
40
30
20
4
5
6
7
9 10 11 12 13
8
VCC − Supply Voltage − V
14 15
150
CL = 3.3 nF
TJ = 25°C
140
130
120
110
100
90
80
70
High Side
60
50
40
Low Side
30
20
4
5
6
7
Figure 5
VCC = 6.5 V
CL = 3.3 nF
120
110
100
High Side
90
80
70
60
Low Side
50
40
30
20
−50
11
12 13
14 15
HIGH-TO-LOW PROPAGATION DELAY TIME
vs
JUNCTION TEMPERATURE
t PHL − High-to-Low Propagation Delay Time − ns
t PLH − Low-to-High Propagation Delay Time − ns
150
130
10
Figure 6
LOW-TO-HIGH PROPAGATION DELAY TIME
vs
JUNCTION TEMPERATURE
140
9
8
VCC − Supply Voltage − V
−25
25
75
0
50
100
TJ − Junction Temperature − °C
125
150
140
130
VCC = 6.5 V
CL = 3.3 nF
120
110
100
90
High Side
80
70
60
50
Low Side
40
30
20
−50
−25
0
25
50
75
100
125
TJ − Junction Temperature − °C
Figure 7
Figure 8
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
9
SLVS223B − NOVEMBER 1999 − REVISED AUGUST 2002
TYPICAL CHARACTERISTICS
DRIVER-OUTPUT FALL TIME
vs
LOAD CAPACITANCE
DRIVER-OUTPUT RISE TIME
vs
LOAD CAPACITANCE
1000
1000
VCC = 6.5 V
TJ = 25°C
t f − Fall Time − ns
t r − Rise Time − ns
VCC = 6.5 V
TJ = 25°C
100
High Side
Low Side
10
1
0.01
1
0.1
10
100
High Side
Low Side
10
1
0.01
100
10
100
CL − Load Capacitance − nF
CL − Load Capacitance − nF
Figure 9
Figure 10
SUPPLY CURRENT
vs
SUPPLY VOLTAGE
SUPPLY CURRENT
vs
SUPPLY VOLTAGE
25
6000
TJ = 25°C
CL = 50 pF
5500
TJ = 25°C
CL = 50 pF
5000
20
4500
ICC − Supply Current − mA
ICC − Supply Current − µ A
1
0.1
500 kHz
4000
300 kHz
3500
200 kHz
3000
100 kHz
50 kHz
25 kHz
2500
2000
1500
1000
2 MHz
15
10
1 MHz
5
500
0
0
4
6
8
10
12
14
16
4
VCC − Supply Voltage − V
8
10
Figure 12
POST OFFICE BOX 655303
12
VCC − Supply Voltage − V
Figure 11
10
6
• DALLAS, TEXAS 75265
14
16
SLVS223B − NOVEMBER 1999 − REVISED AUGUST 2002
TYPICAL CHARACTERISTICS
PEAK SOURCE CURRENT
vs
SUPPLY VOLTAGE
PEAK SINK CURRENT
vs
SUPPLY VOLTAGE
4
4
TJ = 25°C
TJ = 25°C
3.5
3
3
Low Side
Peak Sink Current − A
Peak Source Current − A
3.5
2.5
2
High Side
1.5
Low Side
2.5
2
High Side
1.5
1
1
0.5
0.5
0
0
4
6
8
10
12
14
16
4
6
VCC − Supply Voltage − V
8
Figure 13
14
16
Figure 14
INPUT THRESHOLD VOLTAGE
vs
SUPPLY VOLTAGE
INPUT THRESHOLD VOLTAGE
vs
JUNCTION TEMPERATURE
2.0
2.0
TJ = 25°C
VCC = 6.5 V
V IT − Input Threshold Voltage − V
V IT − Input Threshold Voltage − V
12
10
VCC − Supply Voltage − V
1.8
1.6
1.4
1.2
1.0
4
6
8
10
12
14
16
1.8
1.6
1.4
1.2
1.0
−50
−25
0
25
50
75
100
125
TJ − Junction Temperature − °C
VCC − Supply Voltage − V
Figure 15
Figure 16
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
11
SLVS223B − NOVEMBER 1999 − REVISED AUGUST 2002
APPLICATION INFORMATION
Figure 17 shows the circuit schematic of a 100-kHz synchronous-buck converter implemented with a TL5001A
pulse-width-modulation (PWM) controller and a TPS2835 driver. The converter operates over an input range from
4.5 V to 12 V and has a 3.3-V output. The circuit can supply 3 A continuous load. The converter achieves an efficiency
of 94% for VIN = 5 V, Iload=1 A, and 93% for VIN = 5 V, Iload = 3 A.
VIN
+
C10
100 µF
C5
100 µF
+
R1
1 kΩ
U1
TPS2835
1
2
3
4
5
6
7
BOOT
ENABLE
R6
1 MΩ
14
13
IN
NC
12
CROWBAR HIGHDR
11
BOOTLO
NC
10
SYNC
LOWDR
9
DT
NC
PGND
VCC 8
C15
1.0 µF
Q1
Si4410
R7
3.3 Ω
Q2
Si4410
GND
OUT
U2
TL5001A
2
C2
VCC
0.033 µF
R2
1.6 kΩ
3
COMP
FB
4
5 SCP
RT
7
C6
1000 pF
C4
0.022 µF
R3
180 Ω
R4
2.32 kΩ
GND
C1
1 µF
8
R9
90.9 kΩ
R10
1.0 kΩ
Figure 17. 3.3-V 3-A Synchronous-Buck Converter Circuit
12
3.3 V
C7
100 µF +
C12
100 µF +
C3
0.0022 µF
6 DTC
R8
121 kΩ
C13
10 µF
RTN
C8
0.1 µF
1
L1
27 µH
R11
4.7 Ω
C14
1 µF
C9
0.22 µF
C11
0.47 µF
R5
0Ω
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
SLVS223B − NOVEMBER 1999 − REVISED AUGUST 2002
APPLICATION INFORMATION
Great care should be taken when laying out the PC board. The power-processing section is the most critical
and will generate large amounts of EMI if not properly configured. The junction of Q1, Q2, and L1 should be very
tight. The connection from Q1 drain to the positive sides of C5, C10, and C11 and the connection from Q2 source
to the negative sides of C5, C10, and C11 should be as short as possible. The negative terminals of C7 and
C12 should also be connected to Q2 source.
Next, the traces from the MOSFET driver to the power switches should be considered. The BOOTLO signal from
the junction of Q1 and Q2 carries the large gate drive current pulses and should be as heavy as the gate drive
traces. The bypass capacitor (C14) should be tied directly across VCC and PGND.
The next most sensitive node is the FB node on the controller (terminal 4 on the TL5001A). This node is very
sensitive to noise pickup and should be isolated from the high-current power stage and be as short as possible.
The ground around the controller and low-level circuitry should be tied to the power ground as the output. If these
three areas are properly laid out, the rest of the circuit should not have other EMI problems and the power supply
will be relatively free of noise.
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
13
PACKAGE OPTION ADDENDUM
www.ti.com
10-Dec-2020
PACKAGING INFORMATION
Orderable Device
Status
(1)
Package Type Package Pins Package
Drawing
Qty
Eco Plan
(2)
Lead finish/
Ball material
MSL Peak Temp
Op Temp (°C)
Device Marking
(3)
(4/5)
(6)
TPS2834D
ACTIVE
SOIC
D
14
50
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
-40 to 125
2834
TPS2834DR
ACTIVE
SOIC
D
14
2500
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
-40 to 125
2834
TPS2834PWP
ACTIVE
HTSSOP
PWP
14
90
RoHS & Green
NIPDAU
Level-2-260C-1 YEAR
-40 to 125
TPS2834
TPS2834PWPR
ACTIVE
HTSSOP
PWP
14
2000
RoHS & Green
NIPDAU
Level-2-260C-1 YEAR
-40 to 125
TPS2834
TPS2835D
ACTIVE
SOIC
D
14
50
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
-40 to 125
2835
TPS2835PWP
ACTIVE
HTSSOP
PWP
14
90
RoHS & Green
NIPDAU
Level-2-260C-1 YEAR
-40 to 125
TPS2835
(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)
RoHS: TI defines "RoHS" to mean semiconductor products that are compliant with the current EU RoHS requirements for all 10 RoHS substances, including the requirement that RoHS substance
do not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, "RoHS" products are suitable for use in specified lead-free processes. TI may
reference these types of products as "Pb-Free".
RoHS Exempt: TI defines "RoHS Exempt" to mean products that contain lead but are compliant with EU RoHS pursuant to a specific EU RoHS exemption.
Green: TI defines "Green" to mean the content of Chlorine (Cl) and Bromine (Br) based flame retardants meet JS709B low halogen requirements of
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