UCC27222PWPR 概述
高效 Predictive 技术同步降压驱动器 | PWP | 14 | -40 to 105 FET驱动器 MOSFET 驱动器
UCC27222PWPR 规格参数
是否无铅: | 不含铅 | 是否Rohs认证: | 符合 |
生命周期: | Active | 零件包装代码: | TSSOP |
包装说明: | HTSSOP, | 针数: | 14 |
Reach Compliance Code: | compliant | ECCN代码: | EAR99 |
HTS代码: | 8542.39.00.01 | 风险等级: | 5.28 |
高边驱动器: | YES | 接口集成电路类型: | HALF BRIDGE BASED MOSFET DRIVER |
JESD-30 代码: | R-PDSO-G14 | JESD-609代码: | e4 |
长度: | 5 mm | 湿度敏感等级: | 2 |
功能数量: | 1 | 端子数量: | 14 |
最高工作温度: | 105 °C | 最低工作温度: | -40 °C |
最大输出电流: | 3 A | 标称输出峰值电流: | 3.3 A |
封装主体材料: | PLASTIC/EPOXY | 封装代码: | HTSSOP |
封装形状: | RECTANGULAR | 封装形式: | SMALL OUTLINE, HEAT SINK/SLUG, THIN PROFILE, SHRINK PITCH |
峰值回流温度(摄氏度): | 260 | 认证状态: | Not Qualified |
座面最大高度: | 1.2 mm | 最大压摆率: | 100 mA |
最大供电电压: | 20 V | 最小供电电压: | 8.5 V |
标称供电电压: | 12 V | 表面贴装: | YES |
温度等级: | INDUSTRIAL | 端子面层: | Nickel/Palladium/Gold (Ni/Pd/Au) |
端子形式: | GULL WING | 端子节距: | 0.65 mm |
端子位置: | DUAL | 处于峰值回流温度下的最长时间: | NOT SPECIFIED |
断开时间: | 0.11 µs | 宽度: | 4.4 mm |
Base Number Matches: | 1 |
UCC27222PWPR 数据手册
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PDF下载ꢀꢁ ꢁꢂ ꢃꢂ ꢂꢄ
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SLUS486B − AUGUST 2001 − REVISED JULY 2003
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FEATURES
APPLICATIONS
ꢀ
Maximizes Efficiency by Minimizing
Body-Diode Conduction and Reverse
Recovery Losses
ꢀ
Non-Isolated Single or Multi-phased
DC-to-DC Converters for Processor Power,
General Computer, Telecom and Datacom
Applications
ꢀ
Transparent Synchronous Buck Gate Drive
Operation From the Single Ended PWM Input
Signal
DESCRIPTION
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12-V or 5-V Input Operation
The UCC27221 and UCC27222 are high-speed
synchronous buck drivers for today’s
high-efficiency, lower-output voltage designs.
Using Predictive Gate Driveꢁ (PGD) control
technology, these drivers reduce diode
conduction and reverse recovery losses in the
3.3-V Input Operation With Availability of
12-V Bus Bias
ꢀ
ꢀ
On-Board 6.5-V Gate Drive Regulator
3.3-A TrueDrive Gate Drives for High
Current Delivery at MOSFET Miller
Thresholds
synchronous
rectifier
MOSFET(s).
The
UCC27221 has an inverted PWM input while the
UCC27222 has a non-inverting PWM input.
ꢀ
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Automatically Adjusts for Changing
Operating Conditions
Predictive Gate Driveꢁ technology uses control
loops which are stabilized internally and are
therefore transparent to the user. These loops use
no external components, so no additional design
is needed to take advantage of the higher
efficiency of these drivers.
Thermally Enhanced 14-Pin PowerPAD
HTSSOP Package Minimizes Board Area and
Junction Temperature Rise
FUNCTIONAL APPLICATION DIAGRAM
This closed loop feedback system detects
body-diode conduction, and adjusts deadtime
delays to minimize the conduction time interval.
This virtually eliminates body-diode conduction
while adjusting for temperature, load- dependent
delays, and for different MOSFETs. Precise gate
timing at the nanosecond level reduces the
reverse recovery time of the synchronous rectifier
MOSFET body-diode, reducing reverse recovery
losses seen in the main (high-side) MOSFET. The
lower junction temperature in the low-side
MOSFET increases product reliability. Since the
power dissipation is minimized, a higher switching
frequency can also be used, allowing for smaller
component sizes.
V
IN
UCC27222
IN VHI
6,8 GND G1 13
7
14
PWM
IN
V
OUT
3
VDD
SW 11,12
G2 9,10
4,5 VLO
The UCC27221 and UCC27222 are offered in the
GND
thermally enhanced 14-pin PowerPADꢁ package
GND
OUT
IN
Note: 12-V input system shown. For 5-V input only systems, see Figure 6.
with 2°C/W θ .
jc
Predictive Gate Driveꢁ and PowerPADꢁ are trademarks of Texas Instruments Incorporated.
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Copyright 2002, Texas Instruments Incorporated
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SLUS486B − AUGUST 2001 − REVISED JULY 2003
PWP PACKAGE
(TOP VIEW)
1
2
3
4
5
6
7
14
13
12
11
10
9
N/C
N/C
VDD
VLO
PVLO
AGND
IN
VHI
G1
SW
SWS
G2S
G2
8
PGND
N/C − No internal connection
AVAILABLE OPTIONS
PACKAGED DEVICES
PowerPAD
HTSSOP−14 (PWP)
UCC27221PWP
UCC27222PWP
PWM INPUT
(IN)
T
ꢁ
A
INVERTING
−40ꢂ C to 105ꢂ C
NON-INVERTING
ꢃThe PWP package is available taped and reeled. Add R suffix to device type
(e.g. UCC27221PWPR) to order quantities of 2,000 devices per reel and 90
units per tube.
†}
absolute maximum ratings over operating free-air temperature (unless otherwise noted)
Supply voltage range, VDD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −0.3 to 20 V
Input voltage, VHI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 V
SW, SWS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 V
Supply current, I
including gate drive current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .100 mA
DD,
Sink current (peak) pulsed, G1/G2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.0 A
Source current (peak) pulsed, G1/G2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −4.0 A
Analog input, IN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −3.0 V to V
+ 0.3 V, not to exceed 15 V
DD
Power Dissipation at T = 25°C (PWP package) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 W
A
Operating junction temperature range, T . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −55°C to 115°C
J
Storage temperature range, T . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −65°C to 150°C
stg
Lead temperature soldering 1.6 mm (1/16 inch) from case for 10 seconds . . . . . . . . . . . . . . . . . . . . . . . 300°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.
All voltages are with respect to AGND and PGND. Currents are positive into, negative out of the specified terminal.
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SLUS486B − AUGUST 2001 − REVISED JULY 2003
ELECTRICAL CHARACTERISTICS
V
DD
= 12-V, 1-µF capacitor from VDD to GND, 1-µF capacitor from VHI to SW, 0.1-µF and 2.2-µF capacitor from PVLO to PGND, PVLO tied to
VLO, T = −40ꢂ C to 105ꢂ C for the UCC2722x, T = T (unless otherwise noted)
A
A
J
VLO regulator
PARAMETER
TEST CONDITIONS
MIN
6.2
6.2
6.1
TYP
6.5
6.5
6.5
2
MAX
6.8
6.8
6.9
10
UNIT
V
V
V
V
= 12 V,
I
I
I
= 0 mA
DD
VLO
VLO
VLO
= 20 V,
= 0 mA
Regulator output voltage
V
DD
= 8.5 V,
= 100 mA
DD
Line Regulation
Load Regulation
= 12 V to 20 V
= 0 mA to 100 mA
= 8.5 V
DD
mV
I
15
40
VLO
(1)
Short-circuit current
V
DD
220
7.8
mA
V
Dropout voltage, (VDD at 5% VLO drop)
VLO = 6.175 V,
I
= 100 mA
7.1
8.5
VLO
undervoltage lockout
PARAMETER
TEST CONDITIONS
Measured at VLO
MIN
3.30
3.15
0.07
TYP
3.82
3.70
0.12
MAX
4.40
4.25
0.20
UNIT
Start threshold voltage
Minimum operating voltage after start
Hysteresis
V
bias currents
PARAMETER
TEST CONDITIONS
MIN
3.6
5.5
5.5
TYP
4.7
7.1
10
MAX
5.8
8.5
20
UNIT
V
V
bias current at VLO (ON), 5 V applications only
VLO = 4.5 V,
VDD = 8.5 V
VDD = no connect
LO
mA
bias current
DD
f
IN
= 500 kHz,
No load on G1/G2
input command (IN)
PARAMETER
TEST CONDITIONS
MIN
3.3
TYP
3.6
MAX
3.9
2.8
1
UNIT
High-level input voltage
Low-level input voltage
Input bias current
10 V < VDD < 20 V
10 V < VDD < 20 V
V
2.2
2.5
V
DD
= 15 V
µA
input (SWS)
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNIT
f
= 500 kHz,
t
t
t
maximum,
minimum,
minimum
IN
G2S = 0.0 V
ON, G2
ON, G2
ON, G1
High-level input threshold voltage
1.4
2.0
2.6
V
f
= 500 kHz,
IN
G2S = 0.0 V
0.7
1.0
1.3
Low-level input threshold voltage
Input bias current
f
= 500 kHz,
−100 −300 −500
mV
mA
IN
SWS = 0.0 V
−0.9
−1.2
−1.5
input (G2S)
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNIT
f
= 500 kHz,
t
maximum,
minimum,
IN
SWS = 0.0 V
ON, G2
High-level input voltage
Low-level input voltage
1.4
2.0
2.6
V
f
IN
= 500 kHz,
t
ON, G2
0.7
1.0
1.3
SWS = 0.0 V
Input bias current
G2S = 0 V
−370 −470 −570
µA
NOTE 1: Ensured by design. Not production tested.
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SLUS486B − AUGUST 2001 − REVISED JULY 2003
ELECTRICAL CHARACTERISTICS
V
DD
= 12-V, 1-µF capacitor from VDD to GND, 1-µF capacitor from VHI to SW, 0.1-µF and 2.2-µF capacitor from PVLO to PGND, PVLO tied to
VLO, T = −40ꢂ C to 105ꢂ C for the UCC2722x, T = T (unless otherwise noted)
A
A
J
G1 main output
PARAMETER
TEST CONDITIONS
MIN
0.3
10
−3
3
TYP
0.9
25
MAX
1.5
UNIT
Sink resistance
SW = 0 V,
SW = 0 V,
SW = 0 V,
SW = 0 V,
VHI = 6 V, IN = 0 V,
G1 = 0.5 V
Ω
(2)
Source resistance
VHI = 6 V, IN = 6.5 V, G1 = 5.5 V
VHI = 6 V, IN = 6.5 V, G1 = 3.0 V
45
(1)(2)
Source current
−3.3
3.3
17
A
(1)(2)
Sink current
Rise time
Fall time
VHI = 6 V, IN = 0 V,
G1 = 3.0 V
C = 2.2 nF from G1 to SW,
C = 2.2 nF from G1 to SW,
V
= 20 V
= 20 V
25
25
DD
DD
ns
V
17
G2 SR output
PARAMETER
(2)
TEST CONDITIONS
PVLO = 6.5 V, IN = 6.5 V, G1 = 0.25 V
MIN
5
TYP
15
MAX
30
UNIT
Sink resistance
Source resistance
(1)(2)
Ω
(2)
PVLO = 6.5 V, IN = 0 V,
PVLO = 6.5 V, IN = 0 V
PVLO = 6.5 V, IN = 6.5 V
G2 = 6.0 V
G2 = 3.25 V
G2 = 3.25 V
10
−3
3
20
35
Source current
(1)(2)
−3.3
3.3
17
A
Sink current
(2)
Rise time
C = 2.2 nF from G2 to PGND V
C = 2.2 nF from G2 to PGND V
= 20 V
= 20 V
25
35
DD
ns
Fall time
20
DD
deadtime delay
PARAMETER
TEST CONDITIONS
MIN
60
TYP
80
MAX
100
110
4.7
UNIT
t
t
, IN to G2 falling
, IN to G1 falling
OFF, G2
55
80
OFF, G1
Delay Step Resolution
3.5
4.1
−15
48
t
t
t
t
minimum
maximum
minimum
maximum
ns
ON, G1
ON, G1
ON, G2
−21
38
,
ON G2
NOTE 1: Ensured by design. Not production tested.
2: 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.
t
OFF,G1
3.25 V
UCC27222
IN
t
t
t
ON,G2
OFF,G2
ON,G1
90%
10%
G1
G2
90%
10%
UDG−01042
Figure 1. Predictive Gate Drive Timing Diagram
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SLUS486B − AUGUST 2001 − REVISED JULY 2003
TERMINAL FUNCTIONS
TERMINAL
NAME NO.
DESCRIPTION
I/O
Analog ground for all internal logic circuitry. AGND and PGND should be tied to the PCB ground plane
with vias.
AGND
6
−
G1
G2
13
9
O
O
High-side gate driver output that swings between SW and VHI.
Low-side gate driver output that swings between PGND and PVLO.
Used by the predictive deadtime controller for sensing the SR MOSFET gate voltage to set the
appropriate deadtime.
G2S
IN
10
7
I
I
Digital input command pin. A logic high forces on the main switch and forces off the synchronous
rectifier.
PGND
PVLO
SW
8
5
−
I
Ground return for the G2 driver. Connect PGND to PCB ground plane with several vias.
PVLO supplies the G2 driver. Connect PVLO to VLO and bypass on the PCB.
G1 driver return connection.
12
−
Used by the predictive controller to sense SR body-diode conduction. Connect to SR MOSFET drain
close to the MOSFET package.
SWS
VDD
VHI
11
3
I
I
Input to the internal VLO regulator. Nominal VDD range is from 8.5 V to 20 V. Bypass with at least
0.1 µF of capacitance.
Floating G1 driver supply pin. VHI is fed by an external Schottky diode during the SR MOSFET on-time.
Bypass VHI to SW with an external capacitor.
14
4
I
Output of the VLO regulator and supply input for the logic and control circuitry. Connect VLO to PVLO and
bypass on the PCB.
VLO
O
SIMPLIFIED BLOCK DIAGRAM
N/C
N/C
1
2
14 VHI
13 G1
12 SW
VLO
VLO
REGULATOR
VDD
VLO
3
4
11 SWS
10 G2S
PREDICTIVE
DELAY
CONTROLLER
+
3.82 V/ 3.7 V
PVLO
UVLO
PVLO
AGND
5
6
PVLO
UCC27221
UCC27222
9
8
G2
IN
7
PGND
UDG−01030
5
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SLUS486B − AUGUST 2001 − REVISED JULY 2003
APPLICATION INFORMATION
predictive gate drive technique
The Predictive Gate Driveꢁ technology utilizes a digital feedback system to detect body-diode conduction, and
then adjusts the deadtime delays to minimize it. This system virtually eliminates the body-diode conduction time
intervals for the synchronous MOSFET, while adjusting for different MOSFETs characteristics, propagation and
load dependent delays. Maximum power stage efficiency is the end result.
Two internal feedback loops in the predictive delay controller continuously adjusts the turn on delays for the two
MOSFET gate drives G1 and G2. As shown in Figure 2, t
body-diode conduction in the synchronous rectifier MOSFET Q . The turn-off delay for both G1 and G2, t
and t
are varied to provide minimum
ON,G1
ON,G2
2
OFF,G1
and t
are fixed by propagation delays internal to the device.
OFF,G2
The predictive delay controller is implemented using a digital control technique, and the time delays are
therefore discrete. The turn-on delays, t and t , are changed by a single step (typically 3 ns) every
ON, G1
ON, G2
switching cycle. The minimum and maximum turn-on delays for G1 and G2 are specified in the electrical
characteristics table.
UCC27221
3.25 V
t
OFF,G1
IN
3.25 V
UCC37222
t
t
t
ON,G2
OFF,G2
ON,G1
90%
10%
G1
G2
90%
10%
Figure 2. Predictive Gate Drive Timing Diagram
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SLUS486B − AUGUST 2001 − REVISED JULY 2003
APPLICATION INFORMATION
A typical application circuit for systems with 8.5-V to 20-V input is shown in Figure 3.
VIN
D1
R1
UCC27222
N/C
N/C
VHI
G1
Q1
L1
C1
SW
SWS
G2S
G2
VDD
C
V
IN
OUT
VLO
PVLO
AGND
Q2
C2
Cout
PWM
Input
PGND
IN
GND
GND
Figure 3. System Application: 8.5-V to 20-V Input
selection of VHI series resistor R1 (dV/dt Considerations):
The series resistor R1 may be needed to slowdown the turn-on of the main forward switch to limit the dV/dt which
can inadvertently turn on the synchronous rectifier switch. In nominal 12-V input designs, a R1 value of 4-Ω to
10-Ω can be used depending on the type of MOSFET used and the high-side/low-side MOSFET ratio. In 5-V
or lower input applications however, R1 is not needed.
When the drain-source voltage of a MOSFET quickly rises, inadvertent dV/dt induced turn-on of the device is
possible. This can especially be a problem for input voltages of 12 V or greater. As Q1 rapidly turns on, the
drain-to-source voltage of Q2 rises sharply, resulting in a dV/dt voltage spike appearing on the gate signal of
Q2. If the dV/dt induced voltage spike were to exceed the given threshold voltage, the MOSFET may briefly
turn on when it should otherwise be commanded off. Obviously this undesired event would have a negative
impact on overall efficiency.
Minimizing the dV/dt effect on Q2 can be accomplished by proper MOSFET selection and careful layout
techniques. The details of how to select a MOSFET to minimize dV/dt susceptibility are outlined in SEM−1400,
Topic 2, Appendix A, Section A5. Secondly, the switch node connecting Q1, Q2 and L1 should be laid out as
tight as possible, minimizing any parasitic inductance, which might worsen the dV/dt problem.
If the dV/dt induced voltage spike is still present on the gate Q2, a 4W to 10W value of R1 is recommended to
minimize the possibility of inadvertently turning on Q2. The addition of R1 slows the turn-on of Q1, limiting the
dV/dt rate appearing on the drain-to-source of Q2. Slowing down the turn-on of Q1 will result in slightly higher
switching loss for that device only, but the efficiency gained by preventing dV/dt turn-on of Q2 will far outweigh
the negligible effect of adding R1.
When Q2 is optimally selected for dV/dt robustness and careful attention is paid to the PCB layout of the switch
node, R1 may not be needed at all, and can therefore be replaced with a 0-Ω jumper to maintain high efficiency.
The goal of the designer should not be to completely eliminate the dV/dt turn-on spike but to assure that the
maximum amplitude is less than the MOSFET gate-to-source turn-on threshold voltage under all operating
conditions.
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APPLICATION INFORMATION
selection of bypass capacitor C1
Bypass capacitors should be selected based upon allowable ripple voltage, usually expressed as a percent of
the regulated power supply rail to be bypassed. In all of the UCC27222 application circuits shown herein, C1
provides the bypass for the main (high-side) gate driver. Every time Q1 is switched on, a packet of charge is
removed from C1 to charge Q1’s gate to approximately 6.0 V. The charge delivered to the gate of Q1 can be
found in the manufacturer’s datasheet curves. An example of a gate charge curve is shown in Figure 4.
GATE-TO-SOURCE VOLTAGE
vs
TOTAL GATE CHARGE
8
6
4
2
31 nC
0
0
10
20
30
40
Q6 − Total Gate Charge − nC
Figure 4.
As shown in Figure 4, 31 nC of gate charge is required in order for Q1’s gate to be charged to 6.0 V, relative
to its source. The minimum bypass capacitor value can be found using the following calculation:
Q
G
C1
+
MIN
k ǒVHI * VSWǓ
(1)
where k is the percent ripple on C1, Q is the total gate charge required to drive the gate of Q1 from zero to
G
the final value of (VHI−VSW). In this example gate charge curve, the value of the quantity (VHI−VSW) is taken
to be 6.0 V. This value represents the nominal VLO regulator output voltage minus the forward voltage drop of
the external Schottky diode, D1. For the MOSFET with the gate charge described in Figure 4, the minimum
capacitance required to maintain a 3% peak-to-peak ripple voltage can be calculated to be 172 nF, so a 180-nF
or a 220-nF capacitor could be used. The maximum peak-to-peak C1 ripple must be kept below 0.4 V for proper
operation.
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APPLICATION INFORMATION
selection of MOSFETs
The peak current rating of a driver imposes a limit on the maximum gate charge of the external power MOSFET
driven by it. The limit is based on the amount of time needed to deliver or remove the required charge to achieve
the desired switching speed during turn-on and turn-off of the external transistor. Hence, there are the families
of gate driver circuits with different current ratings.
To demonstrate this, assume a constant time interval for the switching transition and a fixed gate drive
amplitude. A larger MOSFET with more gate charge will require higher current capability from the driver to
turn-on or turn-off the device in the same amount of time. Accordingly, there is a practical upper limit on gate
charge which can be driven by the UCC27222 family of drivers. Considering the current capability of the
TrueDrive output stage and the available dynamic range (delay adjust range) of the Predictive Gate Drive
circuitry, this limit is approximately 120 nC of gate charge.
Some higher current applications require several MOSFETs to be connected parallel and driven by the same
gate drive signal. If their combined gate charge exceeds 120 nC, the rise and fall times of the gate drive signals
will extend and limit the delay adjust range of the PGD circuit in the UCC27222. This may limit the benefits of
the PGD technology under certain operating conditions.
Note that there are additional considerations in the gate drive circuit design which influence the maximum gate
charge of the external MOSFETs. The most significant of these is the operating frequency which, together with
the amount of gate charge, will define the power dissipation in the driver. The allowable power dissipation is a
function of the maximum junction and operating temperatures, thermal and reliability considerations.
selection of bypass capacitor C2
C2 supplies the peak current required to turn on the Q2 synchronous rectifier MOSFET, as well as the peak
current to charge the C1 capacitor through the bootstrap diode. Since the synchronous MOSFET is turned on
with 0 V across its drain-to-source, there is no Miller, or gate-to-drain charge. Therefore the synchronous
MOSFET gate can be modeled as a simple linear capacitance. The value of this capacitance can be found from
the datasheet’s gate charge curve. Referring to Figure 5, the slope of the curve past the Miller plateau indicates
the equivalent gate capacitance. Because the Y-axis is described in volts, the capacitance is actually the inverse
of the slope of the curve. For example, the curve in Figure 4 has a slope of approximately 2 V / 12 nC over the
gate charge range of 10 nC to 40 nC. The equivalent capacitance is 12 nC / 2 V = 6 nF. With the equivalent
capacitance, the minimum bypass capacitor value can be calculated as:
C
EQ
C2
+
MIN
k
(2)
where
ꢀ
ꢀ
C
is the equivalent gate capacitance,
EQ
k is the voltage ripple on C2, expressed as a percentage
For a peak-to-peak ripple of 3%, the minimum C2 capacitor value is calculated to be 200 nF. A 220-nF capacitor
would be used in this case.
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APPLICATION INFORMATION
regulator current and power dissipation
The regulator current can be calculated from the dc or average current required by the two gate drivers. This
current can be expressed as:
ǒC
GǓ
I
+ F
VLO ) Q
EQ
REG
SW
(3)
Assuming all the power dissipation is internal to the device, and the internal bias current is negligible, the power
dissipated by the device is:
ǒC
Ǔ
P
+ F
VLO ) Q VDD
DIS
SW
EQ G
(4)
For a 500-kHz design, using MOSFETs with the gate charge characteristics shown in Figure 4 for both Q1 and
Q2, the average regulator current would be 35 mA, and, when operated from a 12-V input rail, the resulting
power dissipation is calculated to be 420 mW.
systems using 3.3-V or 5-V power input and 12-V gate drive
Figure 5 shows a schematic for systems where the power bus input is 5 V and 12 V is available for powering
the gate drives. This system provides the 6.5-V gate drive to both MOSFETs, while the power stage operates
off the 3.3-V or 5-V bus.
+3.3 V
or +5V
D1
R1
UCC27222
N/C
N/C
VHI
G1
C
Q1
IN
L1
C1
+12 V
VDD
VLO
SW
SWS
G2S
G2
V
OUT
C3
PVLO
Q2
C2
AGND
IN
Cout
PWM
Input
PGND
GND
GND
Figure 5. System Application: 3.3-V or 5-V Power Input with 12 V Available for Gate Drive
Note that the series resistor R1 may be needed to slowdown the turn-on of the main forward switch to limit the
dV/dt which can inadvertently turn on the synchronous rectifier switch. The dV/dt considerations and the
selection of R1 are discussed in the previous section.
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APPLICATION INFORMATION
systems with 5-V input only
The circuit pictured in Figure 6 starts up from a 5-V input bus and provides a 6.5-V gate drive to the power
MOSFETs. This circuit uses a charge pump consisting of D , D and C to effectively double the input voltage
3
4
3
and apply this to the input of the linear regulator. The regulator then regulates the doubled input voltage to the
6.5-V nominal for VLO.
D3
D4
+5V
D1
C3
D2
C2
UCC27222
N/C
N/C
VHI
G1
C
Q1
IN
L1
C1
VDD
VLO
SW
SWS
G2S
G2
V
OUT
C4
PVLO
AGND
Q2
Cout
PWM
Input
IN
PGND
GND
GND
Figure 6. System Application: 5-V-Only Power Input with 6.5-V Gate Drive Using Charge Pump Circuit
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APPLICATION INFORMATION
selecting D , D , and D
4
2
3
Selection of suitable diodes is based upon the conducted peak and average currents. D2 simply provides a path
to charge C2 at converter power-up. Virtually any one of the common BAT54 series of Schottky diodes can be
used. To select D3 and D4, the peak currents of these two diodes need to be taken into account. First, the
average current flowing in both D3 and D4 is the same as the regulator current described in equation (3). The
peak currents in D3 and D4 are described as:
I
REG
I
I
+
+
D3PK
1 * D
(5)
(6)
I
REG
D4PK
D
For most UCC27222 applications, the duty cycle is much less than 50%, and the peak current in D3 is quite
reasonable. However, the peak current in D4 is quite high. This high peak current requires using a diode with
a higher current rating for D4.
To maintain a reasonable charge pump efficiency, BAT54-type diodes can be used for applications where the
peak currents are below approximately 40 mA. For applications where the peak current is greater than 40 mA,
a 350-mA or 500-mA diode should be used. A typical 350-mA diode is SD103CW, SOD−123 package,
manufactured by Diodes Inc. A typical 500-mA diode is the ZHCS500, SOT−23 package, available from Zetex
Inc.
selection of the flying capacitor C3
The flying capacitor is subjected to large peak currents, and to keep the peak-to-peak ripple voltage low, this
capacitor has to be larger than C1 and C2. Selection of C3 should be done based on allowable peak-to-peak
ripple on C3:
I
REG
C3
+
MIN
k ǒVIN * VFD3Ǔ
F
SW
(7)
where I
is the regulator output current, F
is the switching frequency, k is the percent ripple on C3, and
REG
SW
V
is the forward drop of D3.
FD2
selection of bypass capacitor C4
The bypass capacitor C4 needs to be sized to take the peak current from the charge pump diode D4. The
capacitor is sized based on allowable ripple voltage:
(
1 * D)
I
REG
C
+
MIN
k ǒ2 VIN * V
FD4Ǔ
* V
F
FD3
SW
and V
(8)
where V
are the forward voltages of D3 and D4 and k is the percent ripple allowed on C4.
FD4
FD3
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APPLICATION INFORMATION
synchronous rectification and predictive delay
In a normal buck converter, when the main switch turns off, current is flowing to the load in the inductor. This
current cannot be stopped immediately without using infinite voltage. For the current path to flow and maintain
voltage levels at a safe level, a rectifier or catch device is used. This device can be either a conventional diode,
or it can be a controlled active device if a control signal is available to drive it. The UCC27222 provides a signal
to drive an N-channel MOSFET as a rectifier. This control signal is carefully coordinated with the drive signal
for the main switch so that there is minimum delay from the time that the rectifier MOSFET turns off and the main
switch turns on, and minimum delay from when the main switch turns off and the rectifier MOSFET turns on.
This scheme, Predictive Gate Driveꢁ delay, uses information from the current switching cycle to adjust the
delays that are to be used in the next cycle. Figure 7 shows the switch-node voltage waveform for a
synchronously rectified buck converter. Illustrated are the relative effects of a fixed-delay drive scheme
(constant, pre-set delays for the turnoff to turn on intervals), an adaptive delay drive scheme (variable delays
based upon voltages sensed on the current switching cycle) and the predictive delay drive scheme.
Note that the longer the time spent in body-diode conduction during the rectifier conduction period, the lower
the efficiency. Also, not described in Figure 7 is the fact that the predictive delay circuit can prevent the body
diode from becoming forward biased at all while at the same time avoiding cross conduction or shoot through.
This results in a significant power savings when the main MOSFET turns on, and minimizes reverse recovery
loss in the body diode of the rectifier MOSFET.
The power dissipation on the main (forward) MOSFET is reduced as well, although that savings is not as
significant as the savings in the rectifier MOSFET.
During reverse recovery the body diode is still forward biased, thus the reverse recovery current goes through
the forward MOSFET while the drain−source voltage is still high, causing additional switching losses. Without
PGD during this switching transition, Vds = Vin and Ids = Iload + Irr in the main MOSFET. With PGD however,
Vds = Vin and Ids = Iload. The reduction in current accounts for additional power savings in the main MOSFET.
V
IN
0 V
V
D
GND
Channel Conduction
Body Diode Conduction
Fixed Delay
Adaptive Delay
Predictive Delay
UDG−02175
Figure 7. Switch Node Waveforms for Synchronous Buck Converter
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APPLICATION INFORMATION
comparison between predictive and adaptive gate drive techniques
The first synchronous rectifier controllers had a fixed turn-on delay between the two gate drivers. The advantage
of this well-known technique is its simplicity. The drawbacks include the need to make the delay times long
enough to cover the entire application of the device and the temperature and lot-to-lot variation of the time delay.
Since the body-diode of the synchronous rectifier conducts during this deadtime, the efficiency of this technique
varies with different MOSFETs, ambient temperature, and with the lot-to-lot variation of the deadtime delay.
To combat the variability of the internal time delays, second generation controllers used state information from
the power stage to control the turn-on of the two gate drivers. This technique is usually referred to as adaptive
gate drive technique and is pictured in FIgure 8.
V
IN
+
+
ON ON
OFF
V
OUT
UDG−01031
Figure 8. Adaptive Gate Drive Technique
The main advantage of the adaptive technique is the on-the-fly delay adjustment for different MOSFETs and
temperature-variable time delays. The disadvantages include the body-diode conduction time intervals caused
by delays in the cross-coupling loops and the inability to compensate for the delay to charge the MOSFET gates
to the threshold levels. Additionally, it is difficult to determine whether the synchronous MOSFET channel is off
by solely monitoring the SR MOSFET gate voltage. Some devices actually add a programmable delay between
the turn-off of the synchronous rectifier and the turn-on of the main MOSFET via an external capacitor. This
added delay directly affects the power stage efficiency through additional body-diode conduction losses. Since
these losses are centralized in the synchronous MOSFET, the stress and temperature rise in this component
becomes a major design headache.
The third-generation predictive control technique is different from the adaptive technique in that it uses
information from the previous switching cycle to set the deadtime for the current cycle. The adaptive technique
on the other hand uses the current state information to set the delay times. The inherent feedback loop
propagation delays cause body-diode conduction.
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SLUS486B − AUGUST 2001 − REVISED JULY 2003
APPLICATION INFORMATION
adaptive vs. predictive waveforms
Figures 9 through 11 illustrate the adaptive (left) vs. predictive (right) switching waveforms. Key comparison
regions are denoted with (A), (B), (C), (D), and (E) for the adaptive control waveforms and (A′), (B′), (C′), (D′),
and (E′) for the predictive control waveforms. Figures 10 and 11 are close-ups of each transition edge.
At (A), the propagation delay from sensing the synchronous rectifier gate going low to the high-side gate going
high results in approximately 60 ns of body-diode conduction shown at (B). With the predictive drive, as soon
as the body-diode conduction of the SR MOSFET (B) is sensed, the high-side turn-on delay is adjusted to
minimize the body-diode conduction time (B′).
At (A′), the high side gate-to-source voltage is increasing while the synchronous rectifier gate-to-source voltage
is decreasing. A natural result of the precise timing of the high-side MOSFET turn-on is shown at (C) and (C′).
The overshoot and ringing for the predictive drive (C′) has much smaller amplitude than the adaptive drive (C)
due a reduction in reverse recovery in the SR MOSFET body diode. This reduction in reverse recovery is only
possible with the extremely precise gate timing used in the predictive drive technique.
At (D), the propagation delay from the synchronous rectifier drain-to-source voltage falling to the gate-to-source
voltage rising causes the body diode of the SR MOSFET to conduct for approximately 60 ns (E). When the
predictive drive is enabled (D′), the inherent delay is eliminated and virtually no body-diode conduction is shown
at (E′).
Complementary
Gate Drive
Waveforms
2 V / div
D
A
A4
D4
C
C4
VDS of SR
MOSFET
Switch
E4
B4
E
B
2 V / div
Predictive Drive
100 ns / div
Adaptive Drive
100 ns / div
Figure 9. Adaptive vs. Predictive Switching Waveforms
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SLUS486B − AUGUST 2001 − REVISED JULY 2003
APPLICATION INFORMATION
A4
Complementary
Gate Drive
A
Waveforms
2 V / div
C
C4
VDS of SR
MOSFET
Switch
B4
B
2 V / div
Adaptive Drive
20 ns / div
Predictive Drive
20 ns / div
Figure 10. Close-Up: Turn-Off of Synchronous Rectifier Switch to Turn-On of Main Switch
Complementary
Gate Drive
Waveforms
D4
D
2 V / div
VDS of SR
MOSFET
Switch
E4
E
2 V / div
Adaptive Drive
20 ns / div
Predictive Drive
20 ns / div
Figure 11. Close-Up: Turn-Off of Main Switch to Turn-On of Synchronous Rectifier Switch
efficiency comparison
Figures 12 through 15 show a series of efficiency measurements taken at two output voltages (0.9 V and 1.8
V) and two switching frequencies (250 kHz and 500 kHz) for both predictive and adaptive delay techniques.
The efficiency gain using the predictive technique is 1% for a V
of 250 kHz (Figure 12). Figures 13 and 14 show the efficiency gain approximately doubles when V
level of 1.8 V and at a switching frequency
OUT
is lowered
OUT
by a factor of two (to 0.9 V), or when the switching frequency is doubled to 500 kHz. With both doubled frequency
and one-half of the output voltage, the efficiency gain of predictive technology is about 4% over the adaptive
technology (Figure 15). Therefore, as the switching frequency increases and output voltages are lowered, the
efficiency gains are higher. This results in lower operational temperatures for increased reliability as well as
smaller size designs for increased frequencies.
16
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SLUS486B − AUGUST 2001 − REVISED JULY 2003
APPLICATION INFORMATION
EFFICIENCY
vs
EFFICIENCY
vs
OUTPUT CURRENT
OUTPUT CURRENT
96
94
92
90
88
86
84
82
80
0.5
96
0.5
V
V
= 5 V
= 0.9 V
= 250 kHz
IN
OUT
94
92
90
88
86
84
82
80
PREDICTIVE
f
SW
0.4
0.3
PREDICTIVE
0.4
0.3
ADAPTIVE
ADAPTIVE
0.2
0.1
0.0
0.2
0.1
0.0
DELTA POWER
DISSIPATION
78
76
78
76
DELTA POWER
DISSIPATION
V
V
= 5 V
= 1.8 V
= 250 kHz
IN
OUT
f
SW
74
74
0
5
10
15
20
0
5
10
15
20
I
− Output Current − A
I
− Output Current − A
OUT
OUT
Figure 12
Figure 13
EFFICIENCY
vs
EFFICIENCY
vs
OUTPUT CURRENT
OUTPUT CURRENT
96
94
92
90
88
86
84
82
80
1.2
1.0
96
94
92
90
88
86
84
82
80
1.2
1.0
V
V
= 5 V
IN
= 0.9 V
= 500 kHz
OUT
PREDICTIVE
f
SW
PREDICTIVE
0.8
0.6
0.8
0.6
ADAPTIVE
DELTA POWER
DISSIPATION
ADAPTIVE
0.4
0.2
0.4
0.2
78
76
78
76
V
V
= 5 V
= 1.8 V
IN
OUT
= 500 kHz
DELTA POWER
DISSIPATION
f
SW
74
0.0
20
74
0.0
20
0
5
10
15
0
5
10
15
I
− Output Current − A
OUT
I
− Output Current − A
OUT
Figure 14
Figure 15
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SLUS486B − AUGUST 2001 − REVISED JULY 2003
LAYOUT CONSIDERATIONS
packaging
The UCC27221/2 are only available in TI’s thermally enhanced 14-pin PowerPad package. This package
offers exceptional thermal impedance with a junction-to-case rating of 2ꢂC/W. Shown as the crosshatched
region in Figure 16, PowerPad includes an exposed leadframe die pad located on the bottom side of the
package. Exposed pad dimensions for the PowerPadꢁ TSSOP 14-pin package are 69 mils x 56 mils (1.8 mm
x 1.4 mm). However, the exposed pad tolerances can be + 41 / − 2 mils (+ 1.05 /− .05 mm) due to position and
mold flow variation. Effectively removing the heat from the PowerPAD package requires a thermal land area,
shown as the shaded gray region in Figure 16, designed into the PCB directly beneath the package. A minimum
thermal land area of 5 mm by 3.4 mm is recommended as illustrated in Figure 16. Any tolerance variances of
the exposed PowerPad falls well within the thermal land area when the recommended minimum land area
is included on the printed circuit board. In addition, a 2-by-3 array of 13-mil thermal vias is required within the
exposed PowerPad area, as shown in Figure 16. If additional heat sinking capability is required, larger 25-mil
vias can be added to the thermal land area.
Required Vias on PowerPad Area
2 x 3 Array
3.4mm
(0.1339”)
0.65mm
0.33mm
(0.0256”)
(13 mil) dia Vias
Exposed
5.0mm
PowerPad
1.8mm (0.069”)
(0.1968”)
1.05mm
0.3mm
(0.0118”)
(0.0413”)
Optional Vias on Thermal Land Area
0.635mm
Exposed
PowerPad
(25 mil) dia Vias
1.4mm (0.056”)
Figure 16. TSSOP−14PWP Package Outline and Minimum PowerPADE PCB Thermal Land
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SLUS486B − AUGUST 2001 − REVISED JULY 2003
REFERENCE DESIGN AND EVALUATION MODULE
A reference design is discussed in, 12 V to 1.8 V, 20-A High Efficiency Synchronous Buck Converter Using the
UCC27222 with Predictive Gate Driveꢁ, TI Literature Number SLUU140 and accompanying evaluation module
(EVM) SLUP192. The design highlights UCC27222 and its Predictive Gate Driveꢁ synchronous buck operation
using a simple single ended PWM controller. The schematic is shown in Figure 17.
Figure 17. Typical Application Diagram
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SLUS486B − AUGUST 2001 − REVISED JULY 2003
TYPICAL CHARACTERISTICS
UVLO THRESHOLD
vs
TEMPERATURE
BIAS CURRENT
vs
TEMPERATURE (NO LOAD)
16
14
4.2
4.1
4.0
3.9
3.8
3.7
3.6
I
: VDD = 12 V, 500 kHz
DD
12
10
UVLO On
8
6
4
2
0
I
: VDD = 8.5 V, Static
UVLO Off
DD
I
: VLO = 12 V, Static, 5 V Only Systems
VLO
3.5
3.4
3.3
3.2
−50
−25
0
25
50
75
100
125
−50
−25
0
25
T − Temperature − °C
A
50
75
100
125
T
− Temperature − °C
A
Figure 18
Figure 19
VLO LINE REGULATION
vs
VLO LOAD REGULATION
vs
TEMPERATURE (NO LOAD, IVLO = 0 mA)
TEMPERATURE
6.8
6.8
6.7
6.6
6.7
6.6
V
DD
= 20 V
I
= 0 mA
VLO
6.5
6.5
V
DD
= 12 V
I
= 100 mA
VLO
6.4
6.3
6.4
6.3
6.2
6.2
−50
−25
0
25
50
75
100
125
−50
−25
0
25
50
75
100
125
T
A
− Temperature − °C
T
A
− Temperature − °C
Figure 20
Figure 21
20
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ꢀ ꢁꢁ ꢂꢃ ꢂꢂ ꢄ
ꢀ ꢁꢁ ꢂꢃ ꢂꢂ ꢂ
SLUS486B − AUGUST 2001 − REVISED JULY 2003
TYPICAL CHARACTERISTICS
DROPOUT VOLTAGE (VDD AT VLO = 6.175 V)
DROPOUT VOLTAGE (VDD AT VLO = 6.175 V)
vs
vs
OUTPUT CURENT
TEMPERATURE (I
= 100 mA)
VLO
8.6
8.4
8.2
8.0
7.8
7.6
7.4
8.6
8.4
8.2
8.0
7.8
7.6
7.4
7.2
7.0
7.2
7.0
−50
−25
0
25
50
75
100
125
0
50
100
T
A
− Temperature − °C
IVLO − VLO Output Current − mA
Figure 22
Figure 23
VLO SHORT CIRCUIT CURRENT
INPUT THRESHOLD
vs
vs
TEMPERATURE
TEMPERATURE (VDD = 10 V TO 20 V)
4.0
3.5
3.0
2.5
2.0
1.5
1.0
300
Input Threshold Rising
290
280
270
260
Input Threshold Falling
Input Threshold Hyst.
250
240
230
220
210
200
0.5
0.0
−50
−25
0
25
50
75
100
125
−50
−25
0
25
50
75
100
125
T
A
− Temperature − °C
T
A
− Temperature − °C
Figure 24
Figure 25
21
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ꢀ ꢁꢁꢂ ꢃ ꢂ ꢂ ꢄ
ꢀ ꢁꢁꢂ ꢃ ꢂ ꢂ ꢂ
SLUS486B − AUGUST 2001 − REVISED JULY 2003
TYPICAL CHARACTERISTICS
PREDICTIVE DELAY BIT WEIGHT
PROPAGATION DELAYS
vs
vs
TEMPERATURE
TEMPERATURE
4.7
4.5
120
100
t
, G2
OFF
4.3
4.1
80
60
t
, G1
OFF
3.9
3.7
40
20
3.5
0
−50
−25
0
25
50
75
100
125
−50
−25
0
25
50
75
100
125
T
A
− Temperature − °C
T
A
− Temperature − °C
Figure 26
Figure 27
PREDICTIVE DELAY RANGE
PREDICTIVE DELAY RANGE
vs
vs
TEMPERATURE
TEMPERATURE
60
60
50
50
t
, G1 Max
ON
40
30
40
30
t
, G2 Max
ON
20
10
20
10
0
0
t
, G1 Min
t
, G2 Min
ON
ON
−10
−10
−20
−30
−20
−30
−50
−25
0
25
50
75
100
125
−50
−25
0
25
50
75
100
125
T
A
− Temperature − °C
T
A
− Temperature − °C
Figure 28
Figure 29
22
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ꢀ ꢁꢁ ꢂꢃ ꢂꢂ ꢄ
ꢀ ꢁꢁ ꢂꢃ ꢂꢂ ꢂ
SLUS486B − AUGUST 2001 − REVISED JULY 2003
TYPICAL CHARACTERISTICS
G1 RISE AND FALL TIMES
G2 RISE AND FALL TIMES
vs
vs
TEMPERATURE (2.2 nF)
TEMPERATURE (2.2 nF)
30
25
30
25
20
Fall Time
20
Rise Time
15
10
15
Rise Time
Fall Time
10
5
5
0
0
−50
−25
0
25
50
75
100
125
−50
−25
0
25
50
75
100
125
T
A
− Temperature − °C
T
A
− Temperature − °C
Figure 30
Figure 31
G1 SINK RESISTANCE
vs
G1 SOURCE RESISTANCE
vs
TEMPERATURE (R
)
TEMPERATURE
DS(on)
40
35
30
25
20
15
10
5
1.5
1.4
1.3
1.2
1.1
1.0
0.9
0.8
0.7
0.6
0.5
0
−50
−25
0
25
50
75
100
125
−50
−25
0
25
50
75
100
125
T
A
− Temperature − °C
T
A
− Temperature − °C
Figure 32
Figure 33
23
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ꢀ ꢁꢁꢂ ꢃ ꢂ ꢂ ꢄ
ꢀ ꢁꢁꢂ ꢃ ꢂ ꢂ ꢂ
SLUS486B − AUGUST 2001 − REVISED JULY 2003
TYPICAL CHARACTERISTICS
G2 SOURCE RESISTANCE
G2 SINK RESISTANCE
vs
vs
TEMPERATURE
TEMPERATURE (R
)
DS(on)
40
35
30
40
35
30
25
20
25
20
15
10
5
15
10
5
0
0
−50
−25
0
25
50
75
100
125
−50
−25
0
25
50
75
100
125
T
A
− Ambient Temperature − °C
T
A
− Temperature − °C
Figure 34
Figure 35
RELATED PRODUCTS
PART
NUMBER
GATE
DRIVE
DESCRIPTION
PACKAGE
TPS2830/1
TPS2832/3
TPS2834/5
TPS2836/7
TPS2838/9
TPS2848/9
Fast synchronous buck MOSFET drivers with dead-time control
Fast synchronous buck MOSFET drivers with dead-time control
Synchronous buck MOSFET drivers with dead-time control
Synchronous buck MOSFET drivers with dead-time control
Synchronous buck MOSFET drivers with drive regulator
Synchronous buck MOSFET drivers with drive regulator
2.4 A
2.4 A
2.4 A
2.4 A
4 A
PowerPADꢁ HTSSOP−14, SOIC−14
SOIC−8
PowerPADꢁ HTSSOP−14, SOIC−14
SOIC−8
PowerPADꢁ HTSSOP−16
PowerPADꢁ HTSSOP−14
PowerPADꢁ MSOP−10
4 A
TPS40000/1/2/3 Low input voltage mode synchronous buck controller with predictive
gate drive
1 A
REFERENCES
1. Power Supply Design Seminar SEM−1400 Topic 2: Design and Application Guide for High Speed MOSFET
Gate Drive Circuits, by Laszlo Balogh, Texas Instruments Literature Number SLUP169.
2. Power Supply Design Seminar SEM−1400 Topic 7: Implication of Synchronous Rectifiers in Isolated,
Single-Ended, Forward Converters, by Christopher Bridge, Texas Instruments Literature Number
SLUP175.
3. 12 V to 1.8 V, 20 A High-Efficiency Synchronous Buck Converter Using UCC27222 With Predictive Gate
Drive] Technology, TI Literature Number SLUU140.
24
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ꢀ ꢁꢁ ꢂꢃ ꢂꢂ ꢄ
ꢀ ꢁꢁ ꢂꢃ ꢂꢂ ꢂ
ꢐ
SLUS486B − AUGUST 2001 − REVISED JULY 2003
PowerPADꢁ PLASTIC SMALL−OUTLINE
PWP (R−PDSO−G14)
25
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ꢀ ꢁꢁꢂ ꢃ ꢂ ꢂ ꢄ
ꢀ ꢁꢁꢂ ꢃ ꢂ ꢂ ꢂ
SLUS486B − AUGUST 2001 − REVISED JULY 2003
MECHANICAL DATA
PWP (R-PDSO-G**)
PowerPAD PLASTIC SMALL-OUTLINE
20 PINS SHOWN
0,30
0,19
0,65
20
M
0,10
11
Thermal Pad
(See Note F)
0,15 NOM
4,50
4,30
6,60
6,20
Gage Plane
1
10
0,25
A
0°−ā8°
0,75
0,50
Seating Plane
0,10
0,15
0,05
1,20 MAX
PINS **
14
16
20
24
28
DIM
5,10
4,90
5,10
4,90
6,60
6,40
7,90
7,70
9,80
9,60
A MAX
A MIN
4073225/F 10/98
NOTES: A. All linear dimensions are in millimeters.
B. This drawing is subject to change without notice.
C. Body dimensions do not include mold flash or protrusions.
D. The package thermal performance may be enhanced by attaching an external heat sink to the thermal pad.
This pad is electrically and thermally connected to the backside of the die.
E. Falls within JEDEC MO-153
F. The PowerPAD is not directly connected to any leads of the package. However, it is electrically and thermally connected to the
substrate which is the ground of the device. The exposed pad dimension is 1.4 mm x 1.8 mm. However, the tolerances can be
+1.05/−0.05 mm (+ 41 / −2 mils) due to position and mold flow variation.
G. For additional information on the PowerPADꢁ package and how to take advantage of its heat dissipating abilities, refer to Technical
Brief, PowerPad Thermally Enhanced Package, Texas Instrument s Literature No. SLMA002 and Application Brief, PowerPad Made
Easy, Texas Instruments Literature No. SLMA004. Both documents are available at www.ti.com.
26
www.ti.com
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UCC27222PWPR 替代型号
型号 | 制造商 | 描述 | 替代类型 | 文档 |
UCC27222PWPRG4 | TI | 3.3A HALF BRDG BASED MOSFET DRIVER, PDSO14, GREEN, PLASTIC, HTSSOP-14 | 完全替代 | |
UCC27222PWPG4 | TI | 高效 Predictive 技术同步降压驱动器 | PWP | 14 | -40 to 1 | 完全替代 | |
UCC27222PWP | TI | HIGH EFFICIENCY PREDICTIVE SYNCHRONOUS BUCK DRIVER | 类似代替 |
UCC27222PWPR 相关器件
型号 | 制造商 | 描述 | 价格 | 文档 |
UCC27222PWPRG4 | TI | 3.3A HALF BRDG BASED MOSFET DRIVER, PDSO14, GREEN, PLASTIC, HTSSOP-14 | 获取价格 | |
UCC27223 | TI | HIGH-EFFICIENCY PREDICTIVE SYNCHRONOUS BUCK DRIVER WITH ENABLE | 获取价格 | |
UCC27223PWP | TI | HIGH-EFFICIENCY PREDICTIVE SYNCHRONOUS BUCK DRIVER WITH ENABLE | 获取价格 | |
UCC27223PWPG4 | TI | HIGH-EFFICIENCY PREDICTIVE SYNCHRONOUS BUCK DRIVER WITH ENABLE | 获取价格 | |
UCC27223PWPR | TI | HIGH-EFFICIENCY PREDICTIVE SYNCHRONOUS BUCK DRIVER WITH ENABLE | 获取价格 | |
UCC27223PWPRG4 | TI | HIGH-EFFICIENCY PREDICTIVE SYNCHRONOUS BUCK DRIVER WITH ENABLE | 获取价格 | |
UCC27282 | TI | 具有 5V UVLO、互锁和使能功能的 3A、120V 半桥栅极驱动器 | 获取价格 | |
UCC27282-Q1 | TI | 具有 5V UVLO、互锁功能和使能功能的汽车类 3A、120V 半桥驱动器 | 获取价格 | |
UCC27282-Q1-V02 | TI | UCC27282-Q1 Automotive 120-V Half-Bridge Driver with Cross Conduction Protection and Low Switching Losses | 获取价格 | |
UCC27282-Q1_V03 | TI | UCC27282-Q1 Automotive 120-V Half-Bridge Driver with Cross Conduction Protection and Low Switching Losses | 获取价格 |
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