Document
NOT RECOMMENDED FOR NEW DESIGN
USE AH9485/AH9486
AH5792
SINGLE PHASE HALL EFFECT LATXCHXXSXMXART
FAN MOTOR CONTROLLER
Description
The AH5792 is a single chip solution for driving single-coil brush-less DC fans and motors. The AH5792 employs a bidirectional full bridge driver output stage for single coil fan motor applications. The device includes features such as Rotor Lock Protection with rotor lock detection and automatic self-restart to avoid damage to the coil when the rotor is blocked.
The AH5792 also offers an externally controlled Tachometer (Frequency Generator Pin) open-drain output which makes it easier to connect with external interface such as hardware monitoring. The FG is half (1/2) the magnetic change frequency.
Pin Assignments
( Top View )
O2 1
5 FG
VSS 2
NC
O1 3
SOT553
4 Vdd
The devices are packaged in SOT553 and SOT89-5L small outline packages for applications such as small motors like vibration motors or ultra thin cooling fans.
( Top View )
O2 1
5 FG
Vss 2
NC
O1 3
74 Vdd
SOT89-5L
Features
• Support Single-Phase Full Wave Min Fan Driver • Built-in Hall Sensor Input Amplifier • Low Voltage Startup (Vdd = 1.8V) • Lock Detection and Automatic Self-Restart • Without External Timing Capacitor, Reduces the Numbers of
External Component Required • FG Output • Low Profile Package: SOT553 and SOT89-5L • “Green” Molding Compound • Totally Lead-Free & Fully RoHS Compliant (Notes 1 & 2) • Halogen and Antimony Free. “Green” Device (Note 3) • For automotive applications requiring specific change
control (i.e. parts qualified to AEC-Q100/101/200, PPAP capable, and manufactured in IATF 16949 certified facilities), please contact us or your local Diodes representative. https://www.diodes.com/quality/product-definitions/
Applications
• 3.3V / 5V Min. DC Fans (Eight Pole) • Low Voltage / BLDC Motors • Micro-Vibration Motors
Notes:
1. No purposely added lead. Fully EU Directive 2002/95/EC (RoHS), 2011/65/EU (RoHS 2) & 2015/863/EU (RoHS 3) compliant. 2. See https://www.diodes.com/quality/lead-free/ for more information about Diodes Incorporated’s definitions of Halogen- and Antimony-free, "Green" and
Lead-free. 3. Halogen- and Antimony-free "Green” products are defined as those which contain <900ppm bromine, <900ppm chlorine (<1500ppm total Br + Cl) and
<1000ppm antimony compounds.
AH5792
Document number: DS31641 Rev. 8 - 3
1 of 10 www.diodes.com
January 2021
© Diodes Incorporated
Typical Application Circuit (Note 4)
SYSTEM POWER
Vdd D1
C1 Dz
V SS
AH5792
AH5792 XXXXX
SYSTEM POWER
10Kohm
FG
FG
O1 O2
Note:
4. Reverse connection of power supply may break the device. A countermeasure is needed such as using reverse power protection diode D1 between power supply and Vdd terminal. In such case of using reverse power protection diode D1 because of there is no way to return current to power supply, please take necessary measures like below. - Connect Dz (Zener diode) between Vdd and Vss terminal, not to exceed the absolute maximum rating voltage. - Connect a capacitor C1 between Vdd and Vss terminal, to make the path of return current to power supply. The AH5792 has an open-drain tachometer FG output that follows the half (1/2) the magnetic change frequency. A pull-up resistor (10kΩ, typically for System Power = 5V) connected to a supply voltage.
Pin Descriptions (Note 5)
Pin Name
O1
Output Driving & Sinking Pin 1
Vdd
Power Supply Pin
Vss
Ground Pin
FG
Frequency Generator (Note 5)
O2
Output Driving & Sinking Pin 2
NC
No Connection
Note: 5. The FG is half (1/2) the magnetic change frequency.
Description
AH5792
Document number: DS31641 Rev. 8 - 3
2 of 10 www.diodes.com
January 2021
© Diodes Incorporated
Functional Block Diagram
AH5792 XXXXX
Vdd
Power
Hall
Sensor
AMP
V SS
FG Frequency Generator
O1
Logic Full Bridge
Block
Driver
O2
Lock Detector
Operating (Notes 6, 7, 8)
S
Magentic
N
Out 1 Out 2
FG Normal spinning
Ton Toff Mechanical lock
“Re-start spinning”
motor locked detected
motor locked cleared
Notes:
6. In “Normal spinning, the FG shall change its state at each rising edge of OUT2. In “Mechanical lock”, the FG state is kept as the same as the moment of motor locked detected.
7. When magnetic is locked as “S” pole, then out1 is kept on “L”, out2 is a clock with Ton/Toff ratio. When magnetic is locked at “N” pole, then out 2 is kept on “L”, out 1 is a clock with Ton/Toff ratio.
8. When “Re-start spinning” occurs, the motor shall ramp up to the “Normal Spinning” speed from zero. It depends on the motor characteristics.
AH5792
Document number: DS31641 Rev. 8 - 3
3 of 10 www.diodes.com
January 2021
© Diodes Incorporated
Absolute Maximum Ratings (TA = +25C, unless otherwise noted.)
Symbol Vdd
IO(PEAK)
PD TSTG
Supply Voltage
Characteristics
Maximum Output Current (Peak)
Power Dissipation Storage Temperature Range
SOT553 SOT89-5L SOT553 SOT89-5L
.