A8654 Datasheet, PDF (1/29 Pages) Allegro MicroSystems – Wide Input Voltage, Adjustable Frequency, 3 A, 2 MHz Synchronous Buck Regulator

A8654
Wide Input Voltage, Adjustable Frequency,
3 A, 2 MHz Synchronous Buck Regulator
FEATURES AND BENEFITS
• Automotive AEC-Q100 qualified
• Operating voltage range: 4 to 36 V
• UVLO STOP threshold: 2.6 V_TYP
• Maximized duty cycle for low-dropout operation
• Withstands surge voltages up to 40 V
• Capable of 3 A steady-state output current
• Integrated high-side and low-side switching MOSFETs
• Adjustable switching frequency (f_SW): 100 kHz to
2.2 MHz
• Synchronization capability to external clock: 100 kHz to
2.2 MHz
• Frequency dithering for lower EMI signature
• External adjustable compensation network
• Soft-start time externally set via the SS pin
• Pre-bias startup compatible
• Active-low, power-on reset (NPOR) output
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PACKAGES:
16-Pin eTSSOP (LP) with exposed thermal pad
Not to scale
DESCRIPTION
The A8654 is a high output current synchronous buck regulator
that integrates low R_DSON high-side and low-side N-channel
MOSFETs. TheA8654 incorporates PWM current-mode control
to provide simple compensation, excellent loop stability and
fast transient response. The A8654 uses external compensation
to accommodate a wide range of power components to achieve
both excellent loop stability and desirable transient response.
The A8654 regulates nominal input voltages from 4 to
36 V and remains operational when V_IN drops as low as
2.6 V. When the input voltage approaches the output voltage,
the duty cycle is maximized to maintain the output voltage.
The A8654 is able to provide 3 A steady-state load current.
The A8654 features externally set soft-start time, external
compensation network, an EN input to enable V_OUT, a
SYNC/FSET input to synchronize or set the PWM switching
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APPLICATIONS
• Automotive Infotainment • Advanced Driver
Systems
Assistance Systems
□□Audio, Video Navigation □□RADAR, LIDAR,
Systems
mmWave systems
□□Rear Seat Media Display □□Vision and Detection
□□Instrument Clusters
System
□□Telematics
• Industrial
□□General 24 V / 36 V
applications
V_IN
C_IN
VIN
2 × 4.7 µF
GND
EN
BOOT
SW
C_BOOT
100 nF
L_O
C_O
R_FSET
SYNC/FSET
SS
C_SS
22 nF
A8654
NPOR
R_PU
10 kΩ
R_Z
C_P
C_Z
COMP
FB
R_FB1
R_FB2
A8654-DS, Rev. 2
Typical Application Diagram 1