®
RT7028A/B
0.3A/0.6A, High/Low-Side MOSFET Driver
General Description
Features
The RT7028A/B is a high-voltage gate driver IC with dual
outputs. The IC, together with an external bootstrap
network, drives dual n-channel MOSFETs or IGBTs with
input voltage rail up to 600V.
Floating Channels Designed for Bootstrap
Operation with Input Voltage up to 600V
The IC is equipped with a “common-mode dV/dt noise
canceling technique” to provide high dV/dt immunity which
enables stable operation under high dV/dt noise
circumstances. Two Under-Voltage Lockout (UVLO)
functions continuously monitor the bias voltages on VCC
and BOOT-to-LX for preventing malfunction when the bias
voltages are lower than the specified threshold voltages.
The logic level of the PWM signal input pins are compatible
with standard TTL logic level for ease of interfacing with
controlling devices.
300mA/600mA Sourcing/Sinking Current
High dV/dt Immunity : ±50V/ns
VCC and VBOOT − LX Supply Range from 10V to 20V
Under-Voltage Lockout Functions for Both Channels
TTL Compatible Logic Input
Matched Propagation Delay below 50ns
Outputs in Phase with Input (RT7028A) or Out of
Phase with Input (RT7028B)
Ordering Information
RT7028A/B
Package Type
S : SOP-8
Lead Plating System
G : Green (Halogen Free and Pb Free)
Applications
PDP Scan Driver
Fluorescent Lamp Ballast
SMPS
Motor Driver
With Input
A : In Phase
B : Out of Phase
Note :
Richtek products are :
RoHS compliant and compatible with the current requirements of IPC/JEDEC J-STD-020.
Suitable for use in SnPb or Pb-free soldering processes.
Pin Configuration
(TOP VIEW)
VCC
HIN
LIN
GND
8
2
7
VCC
8
BOOT
UGATE
HIN
2
7
UGATE
LIN
3
6
LX
GND
4
5
LGATE
BOOT
3
6
LX
4
5
LGATE
SOP-8
SOP-8
RT7028A
RT7028B
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RT7028A/B
Marking Information
RT7028AGS
RT7028AGS : Product Number
RT7028A
GSYMDNN
RT7028BGS
RT7028BGS : Product Number
RT7028B
GSYMDNN
YMDNN : Date Code
YMDNN : Date Code
Typical Application Circuit
VCC
VCC
DBOOT
1
C1
VCC
BOOT 8
RT7028A
4 GND
2
PWM
Signal
DBOOT
UGATE
CBOOT
7
RUGATE
3 LIN
LGATE 5
C1
RLGATE
VCC
BOOT 8
RT7028B
4 GND
Q1
To Load
LX 6
HIN
1
600V
PWM
Signal
2
UGATE
7
RUGATE
3 LIN
LGATE 5
600V
Q1
To Load
LX 6
HIN
Q2
CBOOT
RLGATE
Q2
Functional Pin Description
Pin No.
1
Pin Name
Pin Function
VCC
Supply voltage input.
HIN (RT7028A)
Logic input for high-side gate driver.
HIN (RT7028B)
Logic input for high-side gate driver.
LIN (RT7028A)
Logic input for low-side gate driver.
LIN (RT7028B)
Logic input for low-side gate driver.
4
GND
Logic ground and low-side driver return.
5
LGATE
Low-side driver output.
6
LX
Return for high-side gate driver.
7
UGATE
High-side driver output.
8
BOOT
Bootstrap supply for high-side gate driver.
2
3
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RT7028A/B
Functional Block Diagram
For RT7028A
BOOT
BOOT-to-LX
Under-Voltage
Lockout
Pulse
Generator
Level
Shifter
UVLO1
Driver
R
Noise
Filter
S
UGATE
Q
LX
UGATE High/Low
VCC
VCC
VCC
UVLO2
Under-Voltage
Lockout
HIN
IIN+
Driver
LGATE High/Low
LIN
Delay
LGATE
GND
IIN+
For RT7028B
BOOT
BOOT-to-LX
Under-Voltage
Lockout
Pulse
Generator
VCC
Level
Shifter
Noise
Filter
UVLO1
Driver
R
S
UGATE
Q
LX
UGATE High/Low
VCC
IIN+
VCC
VCC
UVLO2
Under-Voltage
Lockout
HIN
VCC
Driver
IIN+
LGATE High/Low
LIN
Delay
LGATE
GND
Operation
The RT7028A/B is a high-voltage gate driver for driving
high-side and low-side MOSFETs. The RT7028A/B uses
ultra high voltage device and floating well to allowed UGATE
to drive external MOSFET operating up to 600V. When
the HIN voltage is above the logic-high threshold, the
UGATE voltage goes high to turn on the external MOSFET.
When the HIN voltage is below the logic-low threshold,
the MOSFET is turned off. The operating behavior of the
LGATE, controlled by the LIN pin, is like the behavior of
the UGATE.
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Under-Voltage Lockout (UVLO) Function
When the VCC or BOOT-to-LX voltage is lower the UVLO
threshold, the UGATE and LGATE output will be disabled.
Pulse Generator
The pulse generator is used to transmit the HIN input signal
to the UGATE driver.
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RT7028A/B
Absolute Maximum Ratings
(Note 1)
VCC Supply Voltage, VCC ----------------------------------------------------------------------------------LX to GND ------------------------------------------------------------------------------------------------------BOOT to LX, VBOOT − LX --------------------------------------------------------------------------------------UGATE to LX --------------------------------------------------------------------------------------------------LGATE to GND ------------------------------------------------------------------------------------------------HIN, LIN, HIN, LIN to GND ----------------------------------------------------------------------------------Allowable LX Voltage Slew Rate, dVLX/dt ---------------------------------------------------------------Power Dissipation, PD @ TA = 25°C
−0.3V to 25V
−0.3V to 625V
−0.3V to 25V
−0.3V to VBOOT − LX + 0.3V
−0.3V to VCC + 0.3V
−0.3V to VCC + 0.3V
−50V/ns to 50V/ns
SOP-8 -----------------------------------------------------------------------------------------------------------Package Thermal Resistance (Note 2)
SOP-8, θJA -----------------------------------------------------------------------------------------------------Junction Temperature ----------------------------------------------------------------------------------------Lead Temperature (Soldering, 10 sec.) ------------------------------------------------------------------Storage Temperature Range -------------------------------------------------------------------------------ESD Susceptibility (Note 3)
HBM (Human Body Model)
Except HV pin ------------------------------------------------------------------------------------------------HV (BOOT, UGATE and LX) to GND ---------------------------------------------------------------------
0.53W
Recommended Operating Conditions
188°C/W
150°C
260°C
−65°C to 150°C
2kV
1kV
(Note 4)
VCC Supply Voltage, VCC ----------------------------------------------------------------------------------LX to GND ------------------------------------------------------------------------------------------------------BOOT-to-LX, VBOOT − LX --------------------------------------------------------------------------------------UGATE to LX --------------------------------------------------------------------------------------------------LGATE to GND ------------------------------------------------------------------------------------------------HIN, LIN, HIN, LIN to GND ----------------------------------------------------------------------------------Ambient Temperature Range --------------------------------------------------------------------------------
10V to 20V
0V to 600V
10V to 20V
0V to VBOOT − LX
0 to VCC
0 to VCC
−40°C to 125°C
Electrical Characteristics
(VCC = VBOOT − LX = 15V, TA = 25°C, unless otherwise specified)
Parameter
Symbol
Test Conditions
Min
Typ
Max
Unit
VCC Under-Voltage Lockout
Threshold (On)
VTHON_VCC
7
8.5
10
V
VBOOT LX Under-Voltage
Lockout Threshold (On)
VTHON_BOOT
7
8.5
10
V
VCC Under-Voltage Lockout
Threshold (Off)
VTHOFF_VCC
6.3
7.8
9.3
V
VBOOT LX Under-Voltage
Lockout Threshold (Off)
VTHOFF_BOOT
6.3
7.8
9.3
V
VCC Under-Voltage Lockout
Hysteresis
VHYS_VCC
--
0.7
--
V
VBOOT LX Under-Voltage
Lockout Hysteresis
VHSY_BOOT
--
0.7
--
V
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RT7028A/B
Parameter
Symbol
LX Leakage Current
ILK
VCC Quiescent Current
IQ_VCC
Test Conditions
Min
Typ
Max
Unit
--
--
50
A
--
220
400
A
--
100
200
A
--
--
600
A
--
--
600
A
2.5
--
--
--
--
0.8
50
200
VBOOT = VLX = 600V
BOOT-to-LX Quiescent Current IQ_BOOT LX
VCC Operating Current
IP_VCC
f = 20kHz,
UGATE = LGATE = Open
BOOT-to-LX Operating Current IP_BOOT LX
Logic-High VIH
HIN, LIN, HIN ,
LIN Input Voltage Logic-Low VIL
UGATE, LGATE
Output Voltage
High-Level VOH
Sourcing current = 2mA,
VBOOT VLGATE, VCC VLGATE
--
Low-Level
Sinking current = 2mA,
VUGATE LX, VLGATE
--
20
100
VOL
V
mV
HIN, LIN Input
Current
Logic-High IIN+
HIN = LIN = VCC (RT7028A)
--
2
10
Logic-Low
HIN = LIN = 0V (RT7028A)
1
--
--
HIN , LIN Input
Current
Logic-High IIN
HIN = LIN = VCC (RT7028B)
1
--
--
IIN+
HIN = LIN = 0V (RT7028B)
--
2
10
UGATE and LGATE Sourcing
Current
IO+
UGATE = LX, LGATE = GND,
current pulse width < 10s, low duty
--
290
--
mA
UGATE and LGATE Sinking
Current
IO
UGATE = BOOT, LGATE = VCC,
current pulse width < 10s, low duty
--
600
--
mA
Logic-Low
IIN
A
A
Dynamic Electrical Characteristics (Note 5)
(VCC = VBOOT − LX = 15V, LX = GND, CL = 1000pF, TA = 25°C, unless otherwise specified)
Parameter
Symbol
Test Conditions
Min
Typ
Max
Unit
--
150
220
ns
--
150
220
ns
Turn-On Delay
tON
Turn-Off Delay
tOFF
Turn-On Rising Time
tR
--
70
170
ns
Turn-Off Falling Time
tF
--
35
90
ns
Delay Matching Time, UGATE
and LGATE Turn-On/Off
tM
--
--
50
ns
VLX = 0 or 600V
(Note 6)
Note 1. Stresses beyond those listed “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 in
the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions may
affect device reliability.
Note 2. θJA is measured under natural convection (still air) at TA = 25°C with the component mounted on a high effectivethermal-conductivity four-layer test board on a JEDEC 51-7 thermal measurement standard.
Note 3. Devices are ESD sensitive. Handling precaution is recommended.
Note 4. The device is not guaranteed to function outside its operating conditions.
Note 5. Please refer to the Timing Diagram and Dynamic Waveforms in the Application Information.
Note 6. Turn-off Delay for VLX = 600V is guaranteed by design.
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RT7028A/B
Typical Operating Characteristics
Turn-On Delay Time vs. Temperature
Turn-On Delay Time vs. VCC
400
Turn-On Delay Time (ns)1
Turn-On Delay Time (ns)1
400
300
LGATE
200
UGATE
100
300
LGATE
200
UGATE
100
TA = 25°C
0
0
-50
-25
0
25
50
75
100
125
10
12
14
Temperature (°C)
Turn-Off Delay Time vs. Temperature
18
20
Turn-Off Delay Time vs. VCC
400
400
Turn-Off Delay Time (ns)
Turn-Off Delay Time (ns)
16
VCC (V)
300
200
LGATE
100
UGATE
300
200
LGATE
100
UGATE
TA = 25°C
0
0
-50
-25
0
25
50
75
100
125
10
12
14
Temperature (°C)
Turn-On Rising Time vs. Temperature
18
20
Turn-On Rising Time vs. VCC
160
160
120
UGATE
80
LGATE
Turn-On Rising Time (ns)1
Turn-On Rising Time (ns)1
16
VCC (V)
40
0
120
UGATE
80
LGATE
40
TA = 25°C
0
-50
-25
0
25
50
75
100
Temperature (°C)
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125
10
12
14
16
18
20
VCC (V)
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RT7028A/B
Turn-Off Falling Time vs. Temperature
Turn-Off Falling Time vs. VCC
50
Turn-Off Falling Time (ns)
Turn-Off Falling Time (ns)
50
40
30
UGATE
20
LGATE
10
40
LGATE
30
UGATE
20
10
TA = 25°C
0
0
-50
-25
0
25
50
75
100
125
10
12
14
Temperature (°C)
VCC Operating Current vs. Temperature
20
VCC Operating Current vs. VCC
VCC Operating Current (μA) 1
VCC Operating Current (μA) 1
18
600
400
300
200
100
500
400
300
200
100
TA = 25°C
0
0
-50
-25
0
25
50
75
100
10
125
12
14
Operating Current vs.Temperature
18
20
VBOOT - LX Operating Current vs. VBOOT - LX
300
VBOOT - LX Operating Current (μA)
VBOOT - LX
300
16
VCC (V)
Temperature (°C)
VBOOT - LX Operating Current (μA)
16
VCC (V)
240
180
120
60
240
180
120
60
TA = 25°C
0
0
-50
-25
0
25
50
75
100
Temperature (°C)
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125
10
12
14
16
18
20
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RT7028A/B
LX Leakage Current vs. Temperature
Logic-High Threshold Voltage vs.Temperature
3.0
Logic-High Threshold Voltage (V)1
LX Leakage Current (μA)1
25
20
15
10
5
2.5
HIN
LIN
2.0
1.5
0
1.0
-50
-25
0
25
50
75
100
125
-50
-25
0
Temperature (°C)
HIN
LIN
1
TA = 25°C
Logic-Low Threshold Voltage (V)
Logic-High Threshold Voltage (V)1
3
16
18
1.8
HIN
1.6
LIN
1.4
1.2
-50
20
-25
0
TA = 25°C
0
10
12
14
16
18
VCC (V)
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20
High-Level Output Voltage (mV)1
Logic-Low Threshold Voltage (V)
3
LIN
75
100
125
100
4
1
50
High-Level Output Voltage vs. Temperature
Logic-Low Threshold Voltage vs. VCC
5
HIN
25
Temperature (°C)
VCC (V)
2
125
1.0
0
14
100
2.0
4
12
75
Logic-Low Threshold Voltage vs. Temperature
Logic-High Threshold Voltage vs. VCC
10
50
Temperature (°C)
5
2
25
80
60
HIN
40
LIN
20
0
-50
-25
0
25
50
75
100
125
Temperature (°C)
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Low-Level Output Voltage vs. Temperature
25
100
80
VCC - VLGATE
60
VBOOT - VUGATE
40
20
TA = 25°C
Low-Level Output Voltage (mV)1
High-Level Output Voltage (mV)1
High-Level Output Voltage vs. VCC or VBOOT - LX
20
15
HIN
10
LIN
5
0
0
10
12
14
16
18
-50
20
-25
0
Low-Level Output Voltage vs. VCC or VBOOT - LX
75
100
125
VBOOT - LX Quiescent Current vs. Temperature
125
20
VLGATE
15
VUGATE - LX
10
5
TA = 25°C
0
10
12
14
16
18
VBOOT ? LX Quiescent Current (μA)
25
Low-Level Output Voltage (mV)1
50
Temperature (°C)
VCC or VBOOT - LX (V)
100
75
50
25
0
-50
20
-25
0
VCC or VBOOT - LX (V)
25
50
75
100
125
Temperature (°C)
Output Sourcing Current vs. Temperature
VCC Quiescent Current vs. Temperature
500
Output Sourcing Current (mA)1
400
VCC Quiescent Current (μA) 1
25
300
200
100
400
LGATE
300
UGATE
200
100
0
0
-50
-25
0
25
50
75
100
Temperature (°C)
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125
-50
-25
0
25
50
75
100
125
Temperature (°C)
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RT7028A/B
Output Sinking Current vs.Temperature
Output Sourcing Current vs. VCC or VBOOT - LX
1000
500
400
LGATE
300
200
UGATE
100
TA = 25°C
Output Sinking Current (mA)1
Output Sourcing Current (mA)1
600
800
LGATE
600
UGATE
400
200
0
0
10
12
14
16
18
-50
20
-25
0
50
75
100
125
Temperature (°C)
VCC or VBOOT - LX (V)
Output Sinking Current vs. VCC or VBOOT - LX
VTHON_VCC / VTHOFF_VCC vs.Temperature
800
15
VTHON_VCC / VTHOFF_VCC (V)
Output Sinking Current (mA)1
25
LGATE
600
UGATE
400
200
12
VTHON_VCC
9
VTHOFF_VCC
6
3
TA = 25°C
0
0
10
12
14
16
18
20
VCC or VBOOT - LX (V)
-50
-25
0
25
50
75
100
125
Temperature (°C)
VTHON_BOOT / VTHOFF_BOOT vs.Temperature
VTHON_BOOT / VTHOFF_BOOT (V)
15
12
VTHON_BOOT
9
VTHOFF_BOOT
6
3
0
-50
-25
0
25
50
75
100
125
Temperature (°C)
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RT7028A/B
Application Information
Timing Diagram and Dynamic Waveforms
Figure 1 is the RT7028A/B input / output timing diagram,
and Figure 2, Figure 3 are the definition of dynamic
characteristics. You can know those definitions and the
relationship between input and output from these figures.
For example : tON, tOFF, tR, tF, tM...
VHIN
VLIN
Matched Propagation Delays between Both
Channels
Because the IC internal level shifter circuit causes the
propagation delay of the high-side output signal, shown
in Figure 4. The RT7028A/B adds a propagation delay
matching circuit in the low-side logic circuit, so that highside and low-side output signals approximately
synchronization.
VHIN
VLIN
BOOT
BOOT-to-LX
Under-Voltage
Lockout
Pulse
Generator
VUGATE
VLGATE
Level
Shifter
UGATE High/Low
Figure 1. Input/Output Timing Diagram
HIN
IIN+
VHIN, VLIN
VUGATE
VLGATE
VHIN, VLIN
50%
tON tR
50%
LX
VCC
VCC
UVLO2
Under-Voltage
Lockout
LGATE High/Low
10%
10%
50%
50%
90%
Figure 2. Dynamic Electrical Characteristics Definition
for the RT7028A
50%
50%
tOFF
tF
90%
10%
50%
tM
90%
VUGATE
VLGATE
10%
Figure 3. Dynamic Electrical Characteristics Definition
for the RT7028B
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The junction temperature should never exceed the
absolute maximum junction temperature TJ(MAX), listed
under Absolute Maximum Ratings, to avoid permanent
damage to the device. The maximum allowable power
dissipation depends on the thermal resistance of the IC
package, the PCB layout, the rate of surrounding airflow,
and the difference between the junction and ambient
temperatures. The maximum power dissipation can be
calculated using the following formula :
PD(MAX) = (TJ(MAX) − TA) / θJA
10%
tM
Figure 4. Propagation Delay Matching Circuit
Thermal Considerations
tM
50%
GND
tF
90%
tON tR
LGATE
Delay
IIN+
10%
VHIN, VLIN
S
UGATE
Q
VCC
LIN
tOFF
VUGATE
VLGATE
VUGATE
VLGATE
Driver
R
Driver
tM
VHIN, VLIN
Noise
Filter
UVLO1
where TJ(MAX) is the maximum junction temperature, TA is
the ambient temperature, and θJA is the junction-to-ambient
thermal resistance.
For continuous operation, the maximum operating junction
temperature indicated under Recommended Operating
Conditions is 125°C. The junction-to-ambient thermal
resistance, θJA, is highly package dependent. For a SOP8 package, the thermal resistance, θJA, is 188°C/W on a
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RT7028A/B
standard JEDEC 51-7 high effective-thermal-conductivity
four-layer test board. The maximum power dissipation at
TA = 25°C can be calculated as below :
near the high voltage floating side.
The layout between high-side and low-side power
switches should be thick and straight, avoiding the
formation of long loops. Too long distance will increase
the loop area, and electromagnetic interference
suppression capabilities would be affected. However,
too short distance may cause overheating situation. It
is necessary to consider the most appropriate way.
Refer to typical application circuit, the VCC capacitor
(C1), BOOT to LX capacitor (CBOOT), and bootstrap diode
(DBOOT) need to be placed as close to the IC as possible
to minimize parasitic inductance and resistance. The
CBOOT selected range is from 0.1μF to 0.47μF, and the
VCC capacitor (C1) is greater than ten times CBOOT. It is
recommended to use fast or ultra fast reverse recovery
time bootstrap diode DBOOT.
In Figure 6, the LX pin voltage drop can be improved by
adding RLX (RLX = 1 to 10Ω), because the dv/dt is affected
by (RLX + RUGATE).
PD(MAX) = (125°C − 25°C) / (188°C/W) = 0.53W for a
SOP-8 package.
The maximum power dissipation depends on the operating
ambient temperature for the fixed TJ(MAX) and the thermal
resistance, θJA. The derating curves in Figure 5 allows
the designer to see the effect of rising ambient temperature
on the maximum power dissipation.
Maximum Power Dissipation (W)1
0.6
Four-Layer PCB
0.5
0.4
0.3
0.2
0.1
VCC
0.0
0
25
50
75
100
125
DBOOT
Ambient Temperature (°C)
BOOT
Figure 5. Derating Curve of Maximum Power Dissipation
UGATE
Layout Consideration
LX
A proper PCB layout for power supply can reduce
unnecessary waveform noise and electromagnetic
interference problems to ensure proper system operation,
please refer to the following PCB layout considerations :
For the high voltage and high current loop layout of
power supply should be as thick and short. Avoid
excessive layout generated parasitic inductance and
resistors to cause significant noise.
In order to shorten the length of IC layout, you need to
consider the relative placement for IC and the power
switches. It is recommended that the power switches
placed in a symmetrical manner, and the IC close to
high-side and low-side elements.
In order to reduce the noise coupling, it is recommended
that the ground layout should not be placed under or
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+VDC
CBOOT
RUGATE
Q1
RLX
Figure 6. LX Pin Resister
If the gate current loop opens circuit for some factors,
at this time the current flows through the gate loop via
the power MOSFET drain-to-gate parasitic capacitor. The
current will charge the gate-to-source parasitic capacitor
to result in power MOSFET wrong action. The power
switches can be damaged or burned out, the resisters
(about least 10kΩ) are connected between the gate and
source pin can prevent malfunction of the power
switches.
is a registered trademark of Richtek Technology Corporation.
DS7028A/B-00 October 2017
RT7028A/B
The selection of larger parasitic capacitor power switch
or gate resister may result in too long turn-off time
making the high-side and low-side power switches shoot
through. In order to prevent the situation, reverse parallel
with diodes (DUGATE & DLG Preliminary PreliminaryATE)
in the RUGATE and RLGATE (shown in Figure 7), providing
a fast discharge path for the power switches in a short
time to complete the closing operation.
VCC
+VDC
DBOOT
BOOT
CBOOT
DUGATE
UGATE
RUGATE
Q1
LX
To
Load
DLGATE
LGATE
RLGATE
Q2
Figure 7. Reverse Parallel with Diodes
Copyright © 2017 Richtek Technology Corporation. All rights reserved.
DS7028A/B-00 October 2017
is a registered trademark of Richtek Technology Corporation.
www.richtek.com
13
RT7028A/B
Outline Dimension
H
A
M
J
B
F
C
I
D
Dimensions In Millimeters
Dimensions In Inches
Symbol
Min
Max
Min
Max
A
4.801
5.004
0.189
0.197
B
3.810
3.988
0.150
0.157
C
1.346
1.753
0.053
0.069
D
0.330
0.508
0.013
0.020
F
1.194
1.346
0.047
0.053
H
0.170
0.254
0.007
0.010
I
0.050
0.254
0.002
0.010
J
5.791
6.200
0.228
0.244
M
0.400
1.270
0.016
0.050
8-Lead SOP Plastic Package
Richtek Technology Corporation
14F, No. 8, Tai Yuen 1st Street, Chupei City
Hsinchu, Taiwan, R.O.C.
Tel: (8863)5526789
Richtek products are sold by description only. Richtek reserves the right to change the circuitry and/or specifications without notice at any time. Customers should
obtain the latest relevant information and data sheets before placing orders and should verify that such information is current and complete. Richtek cannot
assume responsibility for use of any circuitry other than circuitry entirely embodied in a Richtek product. Information furnished by Richtek is believed to be
accurate and reliable. However, no responsibility is assumed by Richtek or its subsidiaries for its use; nor for any infringements of patents or other rights of third
parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of Richtek or its subsidiaries.
www.richtek.com
14
DS7028A/B-00 October 2017
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