DATA SHEET
AAT4901
Buffered Power Full Bridge
General Description
Features
The AAT4901 FastSwitch™ is a member of Skyworks'
Application Specific Power MOSFET (ASPM™) product
family. It is a full-bridge buffered power stage operating
with an input voltage range of 2.0V to 5.5V. The device
is designed to operate with a switching frequency of up
to 2MHz, minimizing the cost and size of external components. The AAT4901 is protected from shoot-through
current by integrated break-before-make circuitry. The
drivers can be independently controlled and their propagation delay, from input to output, is typically between
8ns-19ns dependent upon logic option.
• VIN Range: 2.0V–5.5V
• RDS(ON):
High-side 240mΩ
Low-side 200mΩ
• Break-Before-Make Shoot–Through Protection
• 4 Options
Single Control Input with Enable
Two Logic Versions
Dual Control Input with Brake Function
Dual Half-bridge
• Low Quiescent Current:
10μA (max) DC
5mA (max) at 1MHz
• Over-Temperature Protection
• -40°C to +85°C Temperature Range
• SC70JW-8 Package
Four options are offered providing a single input control,
dual input control or as two independent half-bridges.
Other features include low RDS(ON) and low quiescent current allowing for high efficiency performance. The AAT4901
includes thermal protection to safeguard the device under
extreme operating conditions.
Applications
The AAT4901 is available in the space-saving, Pb-free
8-pin SC70JW package and is rated over the -40°C to
+85C temperature range.
DC Motor Drive
Door Locks
Dual Low-Side MOSFET Gate Driver
Fan Motors
High Frequency DC/DC Converters
High Speed Line Drive
Proximity Detectors
Typical Applications
IN
CIN
OUTA
AAT4901-1
ENA
OUTB
ENB
GND
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1
DATA SHEET
AAT4901
Buffered Power Full Bridge
Pin Descriptions
Symbol
Pin #
-1, -2, -4
1
2
3
4
ENA
IN
ENB
N/C
5
6
7
8
Function
-3
Active high enable signal.
Supply voltage input; input voltage range from 2.0V to 5.5V.
Active high enable signal.
4901-1/-2/-4: No connection.
4901-3: Active high enable signal.
Ground connection
Output of half-bridge B. Connect to load.
Output of half-bridge A. Connect to load.
4901-1/-2/-4: No connection.
4901-3: Active high enable signal.
ENC
GND
OUTB
OUTA
N/C
END
Pin Configuration
SC70JW-8
(Top View)
ENA
IN
ENB
N/C
1
8
2
7
3
6
4
5
N/C
OUTA
OUTB
GND
AAT4901-1/-2/-4
2
ENA
IN
ENB
ENC
1
8
2
7
3
6
4
5
END
OUTA
OUTB
GND
AAT4901-3
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DATA SHEET
AAT4901
Buffered Power Full Bridge
Absolute Maximum Ratings1
Symbol
VIN
VEN
VOUT
IMAX
IMAX(PK)
TLEAD
Description
IN to GND
ENA, ENB, ENC, END to GND
OUT to GND
Maximum Continuous Switch Current
Maximum Peak Current
Maximum Soldering Temperature (at Leads)
Value
Units
-0.3 to 6.0
-0.3 to VIN + 0.3
-0.3 to VIN + 0.3
0.7
3
300
V
V
V
A
A
°C
Value
Units
440
225
-40 to 150
mW
°C/W
°C
Thermal Information
Symbol
PD
JA
TJ
Description
Maximum Power Dissipation (TA = 25°C)
Thermal Resistance2
Operating Junction Temperature Range
1. Stresses above those listed in Absolute Maximum Ratings may cause permanent damage to the device. Functional operation at conditions other than the operating conditions
specified is not implied. Only one Absolute Maximum Rating should be applied at any one time.
2. Mounted on a FR4 board.
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com
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3
DATA SHEET
AAT4901
Buffered Power Full Bridge
Electrical Characteristics1
VIN = 5V, TA = -40 to 85°C unless otherwise noted. Typical values are at TA = 25°C.
Symbol
VIN
Description
Conditions
IQAC
AC Quiescent Current
IQDC
DC Quiescent Current
IQ(OFF)
Off-Supply Current
ISD(OFF)
Off-Switch Current
RDS(ON)H
High Side MOSFET On-Resistance
RDS(ON)L
Low Side MOSFET On-Resistance
VONL
VONH
VHYS
ISINK
ENA
ENA
ENA
ENA
TBBM
Break-Before-Make Time
TSHDH
Chip Thermal Shutdown
Temperature
(C), ENB (D) Input Low Voltage
(C), ENB (D) Input High Voltage
(C), ENB (D) Input Hysteresis
(C), ENB (D) Input Leakage
AAT4901-1
AAT4901-2
IN = 5V, ENB (D) = IN,
ENA (C) = 1MHz, IOUT = 0 AAT4901-3
AAT4901-4
AAT4901-1
AAT4901-2
IN = 5V, ENB (D) = IN,
ENA (C) = GND, IOUT = 0
AAT4901-3
AAT4901-4
ENB (D) = ENA (C) = GND, IN = OUT
= 5.5V
ENB (D) = GND, IN = 5.5V, VOUT = 0, or
OUT = IN
VIN = 4.5V
VIN = 3.0V
VIN = 2.0V
VIN = 4.5V
VIN = 3.0V
VIN = 2.0V
Max
Units
V
3
1.6
1.6
0.9
5.5
5
4
4
2.5
5.5
10.0
μA
1.0
μA
1
μA
0.03
240
270
360
200
230
300
m
0.4
ENA (C) , ENB (D) = 5.5V
ENA (C) Rising
ENA (C) Falling
Threshold
Hysteresis
ENA (C) to OUT Delay
ENA (C) = GND
ENB to OUT HiZ Delay
ENA (C) = IN
AAT4901-1
AAT4901-2
AAT4901-3
AAT4901-4
AAT4901-1
AAT4901-2
AAT4901-3
AAT4901-4
AAT4901-1
AAT4901-2
AAT4901-3
AAT4901-4
AAT4901-1
AAT4901-2
AAT4901-3
AAT4901-4
200
0.01
5.0
5.0
145
25
15
15
8
14
18
15
7
19
12
10
10
12
11
10
7
12
mA
m
1.5
ENA (C) Falling
THIZ
Typ
2.0
ENA (C) Rising
TON-DLY
Min
Operation Voltage
1.0
V
V
mV
μA
ns
ns
°C
ns
ns
ns
ns
1. The AAT4901 is guaranteed to meet performance specifications over the –40°C to +85°C operating temperature range and is assured by design, characterization, and correlation with statistical process controls.
4
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DATA SHEET
AAT4901
Buffered Power Full Bridge
Typical Characteristics
AAT4901-2 AC Quiescent Current
vs. Input Voltage
(ENB = IN; ENA = 1MHz; IOUT = 0A; TA = 25°C)
AC Quiescent Current (mA)
AC Quiescent Current (mA)
AAT4901-1 AC Quiescent Current
vs. Input Voltage
4.0
3.3
2.6
1.9
1.2
0.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
5.5
(ENB = IN; ENA = 1MHz; IOUT = 0A; TA = 25°C)
2.1
1.9
1.7
1.5
1.3
1.1
0.9
0.7
0.5
2.0
2.5
3.0
Input Voltage (V)
(ENB = IN; ENA = 1MHz; IOUT = 0A; TA = 25°C)
1.5
1.2
0.9
0.6
0.3
2.5
3.0
3.5
4.0
4.0
4.5
5.0
5.5
AAT4901-4 AC Quiescent Current
vs. Input Voltage
AC Quiescent Current (mA)
AC Quiescent Current (mA)
AAT4901-3 AC Quiescent Current
vs. Input Voltage
0.0
2.0
3.5
Input Voltage (V)
4.5
5.0
5.5
(ENB = IN; ENA = 1MHz; IOUT = 0A; TA = 25°C)
1.5
1.2
0.9
0.6
0.3
0.0
2.0
2.5
3.0
Input Voltage (V)
3.5
4.0
4.5
5.0
5.5
Input Voltage (V)
(ENB = IN; ENA = 0.1kHz~2000kHz; VONH = 2V; IOUT = 0A; TA = 25°C)
(ENB = IN; ENA = 0.1kHz~2000kHz; VONH = 2V; IOUT = 0A; TA = 25°C)
10
1
0.1
0.01
VIN = 5.0V
VIN = 3.0V
0.001
0.1
1
10
100
1000
Switching Frequency (kHz)
10000
AC Quiescent Current (mA)
AAT4901-2 AC Quiescent Current
vs. Switching Frequency
AC Quiescent Current (mA)
AAT4901-1 AC Quiescent Current
vs. Switching Frequency
10
1
0.1
0.01
VIN = 5.0V
VIN = 3.0V
0.001
0.1
1
10
100
1000
10000
Switching Frequency (kHz)
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DATA SHEET
AAT4901
Buffered Power Full Bridge
Typical Characteristics
(ENB = IN; ENA = 0.1kHz~2000kHz; VONH = 2V; IOUT = 0A; TA = 25°C)
(ENB = IN; ENA = 0.1kHz~2000kHz; VONH = 2V; IOUT = 0A; TA = 25°C)
10
1
0.1
0.01
VIN = 5.0V
VIN = 3.0V
0.001
0.1
1
10
100
1000
AC Quiescent Current (mA)
AAT4901-4 AC Quiescent Current
vs. Switching Frequency
AC Quiescent Current (mA)
AAT4901-3 AC Quiescent Current
vs. Switching Frequency
10
1
0.1
0.01
VIN = 5.0V
VIN = 3.0V
0.001
10000
0.1
1
Switching Frequency (kHz)
(ENB = IN, ENA = 1MHz; IOUT = 0A)
4
3
2
0
-40
VIN = 5.0V
VIN = 3.0V
-15
10
35
60
85
VIN = 5.0V
VIN = 3.0V
2
1
0
-40
-15
3
2
1
Temperature (°C)
6
AC Quiescent Current (mA)
AC Quiescent Current (mA)
VIN = 5.0V
VIN = 3.0V
35
35
60
85
AAT4901-3 AC Quiescent Current
vs. Temperature
(ENB = IN, ENA = 1MHz; IOUT = 0A)
10
10
Temperature (°C)
5
-15
10000
3
AAT4901-3 AC Quiescent Current
vs. Temperature
0
-40
1000
(ENB = IN, ENA = 1MHz; IOUT = 0A)
4
Temperature (°C)
4
100
AAT4901-2 AC Quiescent Current
vs. Temperature
AC Quiescent Current (mA)
AC Quiescent Current (mA)
AAT4901-1 AC Quiescent Current
vs. Temperature
1
10
Switching Frequency (kHz)
60
85
2
(ENB = IN, ENA = 1MHz; IOUT = 0A)
VIN = 5.0V
VIN = 3.0V
1.5
1
0.5
0
-40
-15
10
35
60
Temperature (°C)
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DATA SHEET
AAT4901
Buffered Power Full Bridge
Low Side RDS(ON) vs. Output Current
High Side RDS(ON) vs. Output Current
(TA = 25°C)
(TA = 25°C)
350
400
300
350
RDS(ON) (mΩ)
RDS(ON) (mΩ)
Typical Characteristics
250
200
VIN = 4.5V
150
300
250
VIN = 4.5V
200
VIN = 3.0V
VIN = 3.0V
100
150
VIN = 2.0V
VIN = 2.0V
50
100
100
200
300
400
500
600
100
700
200
300
Output Current (A)
Low Side RDS(ON) vs. Temperature
350
400
RDS(ON) (mΩ)
RDS(ON) (mΩ)
450
300
250
200
VIN = 4.5V
150
VIN = 3.0V
VIN = 2.0V
10
35
60
300
250
VIN = 4.5V
200
VIN = 3.0V
VIN = 2.0V
150
-40
85
-15
10
High Side
RDS(ON) (mΩ)
350
Low Side
300
250
200
150
100
4.0
Input Voltage (V)
4.5
5.0
5.5
Enable Threshold Voltage (V)
400
3.5
60
85
AAT4901 Enable A/B/C/D Threshold Voltage
vs. Input Voltage
(IOUT = 0.7A; TA = 25°C)
3.0
35
Temperature (°C)
MOSFETs RDS(ON) vs. Input Voltage
2.5
700
350
Temperature (°C)
2.0
600
(IOUT = 0.7A)
400
-15
500
High Side RDS(ON) vs. Temperature
(IOUT = 0.7A)
100
-40
400
Output Current (A)
1.4
1.2
1
0.8
VIH, -40°C
VIL, -40°C
VIH, 25°C
VIL, 25°C
VIH, 85°C
VIL, 85°C
0.6
0.4
0.2
0
2
2.5
3
3.5
4
4.5
5
5.5
Input Voltage (V)
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DATA SHEET
AAT4901
Buffered Power Full Bridge
Functional Block Diagram
IN
OUTA
OUTB
ENA
ENC
Control Logic
ENB
END
AAT4901-3 Only
GND
Functional Description
The AAT4901 is a buffered full-bridge driver IC with
options to allow the device to function as two independent
half-bridges. The output stage is capable of driving output
loads of up to 0.7A and features break-before-make timing and very fast propagation delay time, allowing high
switching speed up to 2MHz. The enable input (EN), when
8
driven low, turns off the driver and reduces the operating
current to less than 1μA. Over-temperature shutdown
protects the AAT4901 in the case of overload or defective
MOSFET. Logic options allow the AAT4901 to be used as a
small DC motor driver with break function, a solenoid
driver, a dual-low-side MOSFET driver, or as a coil driver.
Applications include motor drive, proximity detectors,
electronic locks, and DC-DC converters.
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DATA SHEET
AAT4901
Buffered Power Full Bridge
Options
AAT4901-1/-4 Logic Table
AAT4901-1
-1
H-bridge configuration with two enables. Enable B is
active high and enables the H-bridge output. Enable A
toggles the H-bridge outputs A and B in anti-phase. In
steady state, this can provide forward/reverse motor
drive signals.
AAT4901-2
H-bridge configuration with two enables. Enable A and
Enable B are in anti-phase and provide forward/reverse
and braking.
ENA
ENB
ENA
ENB
OUTA
OUTB
0
1
0
1
0
0
1
1
0
1
1
0
0
1
0
1
Hi Z
Hi Z
IN
GND
Hi Z
Hi Z
GND
IN
AAT4901-2 Logic Table
ENA
ENB
OUTA
OUTB
0
1
0
1
0
0
1
1
Hi Z
IN
GND
IN
Hi Z
GND
IN
IN
AAT4901-3
Dual independent half-bridge configuration with four
enables. Function similar to 2 x AAT4900.
AAT4901-4
-4
AAT4901-3 Logic Table
H-bridge with two enables. Enable A and Enable B are in
anti-phase and toggle the H-bridge outputs A and B in
anti-phase respectively. In steady state, this can provide
forward/reverse motor drive signals to adjust the motor
speed by various duty cycles.
ENA/C
ENB/D
OUTA/B
0
1
0
1
0
0
1
1
Hi Z
Hi Z
IN
GND
Timing Diagram
TON-DLY-F
V_ENA
50%
50%
50%
50%
T ON-DLY-R
90%
(OFF)
(OFF)
Hi Z
Hi Z
V_OUTA
10%
TON-DLY-R
V_ENB
TON-DLY-F
50%
50%
50%
50%
90%
(OFF)
(OFF)
Hi Z
Hi Z
V_OUTB
10%
TON-DLY-F
TON-DLY-R
THIZ_GND
THIZ_IN
Figure 1: AAT4901-4 Timing Diagram.
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9
DATA SHEET
AAT4901
Buffered Power Full Bridge
Application Information
Input Supply Capacitor
The input capacitor provides a low impedance loop for
the edges of pulsed current drawn by the AAT4901 and
reduces the surge current drawn from the input power.
A 4.7μF to 10μF X7R or X5R low ESR/ESL ceramic capacitor is selected for the input supply decoupling. To minimize the tray resistance, the capacitor should be placed
as closely as possible to the input pin. This keeps the
high frequency content of input current localized, minimizing EMI and input voltage ripple.
Shoot-Through Protection
The internal high-side and low-side MOSFETs of the
AAT4901 cannot conduct at the same time to prevent
shoot-through current. When the high-side MOSFET
turns on, the low-side MOSFET turns off first; after 5ns
break-before-make time, the high-side MOSFET then
turns on. Similarly, before the low-side MOSFET turns
on, the high-side MOSFET turns off; after a certain
break-before-make time (5ns typ.), the low-side MOSFET
turns on. The dead time between the high-side and lowside turn-on should be kept as low as possible to minimize current flows through the body diode of the highside and/or low-side MOSFET(s). The break-before-make
shoot-through protection significantly reduces losses
associated with the driver at high frequency.
Thermal Calculations
TJ(MAX) - TA
θJA
= IQAC · VCC + QG(tot)FSW · VCC
10
TJ(MAX) = junction temperature of the dice (°C).
TA = ambient temperature (°C).
θJA = thermal resistance (225°C/W).
IQAC = AC quiescent current of the driver (mA).
QG(tot) = total gate charge of external low side MOSFETs
(nC).
FSW = switching frequency (MHz).
The maximum junction temperature for the SC70JW-8
package can be derived from Equation 1:
Eq. 2: TJ(MAX) = PD(MAX) · θJA + TA
For example, if the AAT4901 drives 2 AAT9560 MOSFETs
whose maximum gate charge is specified as 13nC for
VGATE = 5V, the total power dissipation in the driver at a
switching frequency of 1MHz equals:
PD(tot) = 2 · (5V · 13nC · 1MHz) + 5V · 4.0mA = 150mW
Gate Drive Current Ratings
Assuming that the maximum gate charge of the dual
low-side MOSFETs are equal, the maximum gate drive
capability for the designed maximum junction temperature without an external resistor can be derived from
Equation 1:
Eq. 3: QG(MAX) =
In the dual low-side MOSFET driver application, the power
dissipation of the AAT4901 includes the power dissipation
in the MOSFETs due to charging and discharging the gate
capacitance, the AC quiescent current power dissipation,
and transient power in the driver during output transitions. As the transient power is usually very small, its
losses can be ignored. Maximum package power dissipation can be estimated by the following equation:
Eq. 1: PD(MAX) = VCC · IIN =
Where:
1
·
2 · FSW
TJ(MAX) - TA
- IQAC
θJA · VIN
The relationship between gate capacitance, turn-on/
turn-off time, and the MOSFET driver current rating can
be determined by:
Eq. 4: IG(MAX) = CG(MAX) ·
dV
dt
Where:
IG(MAX) = peak drive current for a given voltage
CG(MAX) = maximum gate capacitance
dV = MOSFET gate-to-source voltage
dt = rising time of MOSFET gate-to-source voltage
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DATA SHEET
AAT4901
Buffered Power Full Bridge
The relationship between CG(MAX) , QG(MAX) , and VGATE is
given by:
Eq. 5: CG(MAX) =
QG(MAX)
VGATE
The peak current drive requirements for a given MOSFET
gate voltage can be derived from Equations 4 and 5:
Eq. 6: IG(MAX) =
QG(MAX)
dt
Design Example
VIN = 5V
VGATE = 5V
FSW = 1MHz
θJA = 225°C/W
IQAC = 4.0mA
TJ(MAX) = 120°C
TA = 85°C
tRISE = dt = 10ns
QG(MAX) =
1
120°C - 85°C
·
- 4.0mA = 13.6nC
2 · 1MHz 225°C/W · 5V
QG(MAX) 13.6nC
CG(MAX) =
=
= 2.7nF
VGATE
5V
IG(MAX) =
QG(MAX) 13.6nC
=
= 1.36A
dt
10ns
Typical Applications
2-Phase Synchronous Buck Converter
The most common AAT4901 applications include multiphase DC/DC converter output power stages, DC motor
drive, a dual low-side MOSFET driver, and a 3-state highspeed high-current line driver.
Figure 2 shows a typical configuration when used as a
2-phase buck converter power stage with synchronous
rectification. The EN pin can be used to force outputs
OUTA/OUTB to a high impedance state; this allows the
output inductor to operate in discontinuous condition
mode (DCM) and improves efficiency under light load
conditions. The body diode associated with the low-side
switching device gives the AAT4901 inductive switching
capability, and clamps the LX node at one diode drop
below GND during the break-before-make time. The
multiphase buck converter assures a stable, high-performance topology for high currents and low voltages which
are demanded in computers, workstation, telecom and
datacom servers. Figure 3 illustrates output ripple current reduction due to 2-phase cancellation.
Motor Drive
The AAT4901 is ideally suited for use as an efficient output driver for DC motor control due to its full-bridge
output stage with integrated MOSFETs. The inductive
load switching capability of the AAT4901 eliminates the
need for external diodes during commutation time. In
applications where rotation is always in the same direction, a single half-bridge AAT4900 can be used to drive
a DC motor. If needed to control the rotation in both
directions, full-bridge motor control circuits can be
applied as shown in Figure 4. In this configuration the
motor can be controlled to run clockwise, counter-clockwise, stop rapidly (“regeneration” braking) or free run
(coast) to a stop.
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com
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11
DATA SHEET
AAT4901
Buffered Power Full Bridge
On/Off (EN)
VIN: 2.0V ~ 5.5V
VCC
PWM1
SW1
CIN
GND
FB
2 -Phase
DC/DC
Controller PWM2
SW2
1
2
3
4
ENA
END
IN
OUTA
AAT4901-3
ENB
OUTB
ENC
GND
8
7
IL1
6
IL2
L1
IL1 + IL2
VOUT
L2
5
R1
CO
R2
Figure 2: AAT4901 in 2-Phase Synchronous Buck Converter Power Stage.
OUTA
OUTB
IL2
IL1
IL1+IL2
Figure 3: Output Current Ripple Reduction (IL1+IL2) due to 2-Phase Cancellation.
When the voltage applied between the DC motor by the
input(s) logic control is reversed, it could change the
rotation direction. When both outputs (OUTA/OUTB) are
floating, the motor winding acts as a regeneration; the
current inside the motor winding would continue to flow
into the input capacitor through the internal MOSFET
parasitic diode and decay to zero rapidly, stopping the
motor rapidly. When both outputs are connected to the
input supply (or ground) simultaneously, the motor
coasts and the winding current decays slowly due to the
winding resistor until the motor free runs to a stop.
The speed of a DC motor is directly proportional to the
supply voltage. It can be controlled by simply adjusting
the voltage sent to the motor, but this is quite inefficient.
12
A better method is to switch the motor’s supply on and
off rapidly. If the switching is fast enough, the motor
doesn’t notice it, it only notices the average effect. The
time it takes a motor to speed up and slow down under
switching conditions is dependent on the inertia of the
rotor (basically how heavy it is) and the amount of friction and load torque. Figure 5 shows the speed of a motor
that is being turned on and off at a fairly low switching
frequency. The average speed is around 150, although it
varies quite a bit. If the supply voltage is switched quickly enough, the motor will not have time to change speed
much and the speed will be quite steady. When the duty
cycle (D = TON/T) is increased, the average speed of the
motor increases. Thus the speed is controlled by the duty
cycle of the PWM (Pulse Width Modulation).
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com
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DATA SHEET
AAT4901
Buffered Power Full Bridge
VIN: 2.0~5.5V
VIN: 2.0~5.5V
1
CLK/DIR
8
ENA
2
EN
IN
OUTA
AAT4901-1
3
4
C1
4.7μF/16V
ENB
OUTB
N/C
GND
1
CLK/DIR
Brake
N/C
7
2
M
6
CLK/DIR
3
Brake
5
4
C1
4.7μF/16V
ENA
N/C
IN
OUTA
AAT4901-2
ENB
OUTB
N/C
GND
8
7
M
6
5
VIN: 2.0~5.5V
VIN: 2.0~5.5V
EN
1
CLK/DIR
8
ENA
CLK/DIR
END
2
1
N/C
ENA
8
7
IN
2
M
OUTA
AAT4901-3
3
IN
6
ENB
OUTB
ENC
GND
3
OUTA
AAT4901-4
ENB
OUTB
N/C
GND
7
M
6
5
4
4
C1
4.7μF/16V
5
C1
4.7μF/16V
Figure 4: Full-Bridge Motor Driver Using AAT4901.
200
20
Motor Speed
15
100
10
Supply Voltage
50
Supply Voltage
Motor Speed
150
5
0
0
Ton
T
Time
Figure 5: Motor Speed vs. Supply Voltage.
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com
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13
DATA SHEET
AAT4901
Buffered Power Full Bridge
There is also a diode connected in reverse across the field
winding, to absorb the current in the field winding when
all four MOSFETs in the bridge are turned off.
The minimum switching frequency is chosen based on
motor characteristics (the equivalent inductance and the
parasitic series resistor) and the percentage of current
variation to the average current specified. The minimum
switching frequency is in direct proportion to the parasitic series resister, and in inverse proportion to the
equivalent inductance and allowable current ripple.
During period (A), to make the motor run forwards, Q4
is turned on, and Q1 has the PWM signal applied to it.
The current path is shown in blue in Figure 7. At period
(B) Q4 is kept on, so when the Q1 PWM signal is off, current can continue to flow around the bottom loop
through Q3’s parasitic diode. At period (C), to make the
motor run backwards or control the speed, Q3 is turned
on, and Q2 has the PWM signal applied to it. At period
(D), Q3 is kept on, so when the Q2 PWM signal is off,
current can continue to flow around the bottom loop
through Q4’s parasitic diode. At period (E), when the
motor is running forwards for example, the motor is now
acting as a generator and forcing current through its
armature, through Q2’s diode, through the battery
(thereby charging the battery) and back through Q3’s
diode.
When driving a high-voltage DC motor, external highvoltage MOSFETs are needed to commutate the motor.
In this application, the AAT4901 can be configured as a
double-ended gate driver, as illustrated in Figure 6.
The full-bridge power stage operates the motor drive control as shown in Figure 7. Each side of the motor can be
connected either to the battery's positive terminal or to
the battery's negative terminal through the switch. Note
that only one MOSFET on each side of the motor may be
turned on at any one time; otherwise the high-side and
low-side MOSFETs will short out the battery and burn out.
High-Voltage
Rail
VIN: 5.0V
CLK1
1
2
CLK2
3
4
C1
4.7μF/16V
ENA
N/C(END)
IN
OUTA
AAT4901-1,-2,-4
(-3)
ENB
OUTB
N/C(ENC)
GND
8
7
to Motor
6
5
Figure 6: Double-Ended Gate Driver.
14
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com
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DATA SHEET
AAT4901
Buffered Power Full Bridge
VBAT +
VBAT +
Lf
Lf
Field winding
Field winding
Q1
Q2
Q1
Q2
La
La
Ia
Ia
Q3
armature
Q4
Q3
VBAT -
armature
Q4
VBAT Period (A)
Period (B)
VBAT +
VBAT +
Lf
Field winding
Lf
Q1
Field winding
Q2
Q1
La
Q2
La
Ia
Q3
armature
Ia
Q4
Q3
VBAT -
armature
Q4
VBAT Period (D)
Period (C)
VBAT +
Lf
Field winding
Q1
Q2
La
Ia
Q3
armature
Q4
VBAT Period (E)
Figure 7: Full-Bridge Motor Drive Control.
Dual Channel, High Speed,
High Current 3-State Line Driver
The AAT4901-3 is ideally suited for dual channel, high
speed, high current 3-state line driver applications such
as CCD clock drivers. The low quiescent power dissipation
makes this part attractive in battery powered products.
The 3A peak drive capability also makes the AAT4901-3
an excellent choice for driving high speed capacitive
lines. The 20ns fast switching/delay time allows clocking
speeds up to 10MHz.
Dual Low-Side MOSFET Driver
The AAT4901-3 is also ideally suited for dual low-side
MOSFET driver applications due to its dual independent
half-bridge output configuration. It can be used in a
push-pull topology as illustrated in Figure 9 or in other
applications which require the ability to drive the
MOSFETs quickly, due to the AAT4901's extremely low
RDS(ON) (240mΩ typ.) and very fast propagation time
(20ns typ.)
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com
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15
DATA SHEET
AAT4901
Buffered Power Full Bridge
ENA
3-State
IN
ENB
OUTA
ENC
OUTB
END
3-State
GND
Figure 8: AAT4901-3 Dual Channel High-Speed High-Current 3-State Line Driver.
VOUT
VIN
+
+
VCC: 5.0V
EN
PWM A
1
2
3
PWM B
4
ENA
END
OUTA
IN
AAT4901-3
ENB
OUTB
ENC
GND
8
7
6
5
C1
4.7μF/16V
Figure 9: Push-Pull Topology MOSFET Driver with AAT4901.
16
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com
202218B • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • March 20, 2014
DATA SHEET
AAT4901
Buffered Power Full Bridge
OUTA
VIN
U1
AAT4901
C
C1
3
1
JP1 2
3
1
JP2 2
1
3
4
8
3
1
JP3 2
3
1
JP4 2
L1
ENA
IN
ENB
OUTA
ENC
OUTB
END
GND
2
7
6
TP1
Load
Motor
5
C2
L2
TP2
C3
OUTB
4.7μF
M1
GND
M2
GND
M3
GND
M4
Figure 10: AAT4901 Evaluation Board Schematic.
Figure 11: AAT4901 Evaluation Board
Top Side Layout.
Figure 12: AAT4901 Evaluation Board
Bottom Side Layout.
Component
Part Number
Description
Manufacturer
U1
C1
C2, C3
L1, L2
Load
AAT4901
GRM21BR61C475KA88
Not Populated
Not Populated
Not Populated
Buffered Power Full Bridge
Cap Ceramic 4.7μF 0805 X5R 16V 10%
Skyworks
Murata
Table 1: AAT4901 Evaluation Board Bill of Materials.
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com
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17
DATA SHEET
AAT4901
Buffered Power Full Bridge
Ordering Information
Package
Marking1
Part Number (Tape and Reel)2
SC70JW-8
SC70JW-8
SC70JW-8
SC70JW-8
D2RYY
D3RYY
D4RYY
2SRYY
AAT4901IJS-1-T1
AAT4901IJS-2-T1
AAT4901IJS-3-T1
AAT4901IJS-4-T1
Skyworks Green™ products are compliant with
all applicable legislation and are halogen-free.
For additional information, refer to Skyworks
Definition of Green™, document number
SQ04-0074.
Package Information
SC70JW-8
2.20 ± 0.20
1.75 ± 0.10
0.50 BSC 0.50 BSC 0.50 BSC
0.225 ± 0.075
2.00 ± 0.20
0.100
7° ± 3°
0.45 ± 0.10
4° ± 4°
0.05 ± 0.05
0.15 ± 0.05
1.10 MAX
0.85 ± 0.15
0.048REF
2.10 ± 0.30
All measurements in millimeters.
1. XXGYY: XX denotes Device code, G denotes assembly code, and YY denotes date code.
2. Sample stock is generally held on part numbers listed in BOLD.
18
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com
202218B • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • March 20, 2014
DATA SHEET
AAT4901
Buffered Power Full Bridge
Copyright © 2012-2014 Skyworks Solutions, Inc. All Rights Reserved.
Information in this document is provided in connection with Skyworks Solutions, Inc. (“Skyworks”) products or services. These materials, including the information contained herein, are provided by Skyworks as a
service to its customers and may be used for informational purposes only by the customer. Skyworks assumes no responsibility for errors or omissions in these materials or the information contained herein. Skyworks may change its documentation, products, services, specifications or product descriptions at any time, without notice. Skyworks makes no commitment to update the materials or information and shall have no
responsibility whatsoever for conflicts, incompatibilities, or other difficulties arising from any future changes.
No license, whether express, implied, by estoppel or otherwise, is granted to any intellectual property rights by this document. Skyworks assumes no liability for any materials, products or information provided hereunder, including the sale, distribution, reproduction or use of Skyworks products, information or materials, except as may be provided in Skyworks Terms and Conditions of Sale.
THE MATERIALS, PRODUCTS AND INFORMATION ARE PROVIDED “AS IS” WITHOUT WARRANTY OF ANY KIND, WHETHER EXPRESS, IMPLIED, STATUTORY, OR OTHERWISE, INCLUDING FITNESS FOR A PARTICULAR
PURPOSE OR USE, MERCHANTABILITY, PERFORMANCE, QUALITY OR NON-INFRINGEMENT OF ANY INTELLECTUAL PROPERTY RIGHT; ALL SUCH WARRANTIES ARE HEREBY EXPRESSLY DISCLAIMED. SKYWORKS DOES
NOT WARRANT THE ACCURACY OR COMPLETENESS OF THE INFORMATION, TEXT, GRAPHICS OR OTHER ITEMS CONTAINED WITHIN THESE MATERIALS. SKYWORKS SHALL NOT BE LIABLE FOR ANY DAMAGES, INCLUDING BUT NOT LIMITED TO ANY SPECIAL, INDIRECT, INCIDENTAL, STATUTORY, OR CONSEQUENTIAL DAMAGES, INCLUDING WITHOUT LIMITATION, LOST REVENUES OR LOST PROFITS THAT MAY RESULT FROM
THE USE OF THE MATERIALS OR INFORMATION, WHETHER OR NOT THE RECIPIENT OF MATERIALS HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
Skyworks products are not intended for use in medical, lifesaving or life-sustaining applications, or other equipment in which the failure of the Skyworks products could lead to personal injury, death, physical or environmental damage. Skyworks customers using or selling Skyworks products for use in such applications do so at their own risk and agree to fully indemnify Skyworks for any damages resulting from such improper
use or sale.
Customers are responsible for their products and applications using Skyworks products, which may deviate from published specifications as a result of design defects, errors, or operation of products outside of published parameters or design specifications. Customers should include design and operating safeguards to minimize these and other risks. Skyworks assumes no liability for applications assistance, customer product
design, or damage to any equipment resulting from the use of Skyworks products outside of stated published specifications or parameters.
Skyworks, the Skyworks symbol, and “Breakthrough Simplicity” are trademarks or registered trademarks of Skyworks Solutions, Inc., in the United States and other countries. Third-party brands and names are for
identification purposes only, and are the property of their respective owners. Additional information, including relevant terms and conditions, posted at www.skyworksinc.com, are incorporated by reference.
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com
202218B • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • March 20, 2014
19
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