Three-Phase Sensorless Fan Driver
A4941
2
Allegro MicroSystems, LLC
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
Pin-out Diagram
Absolute Maximum Ratings
Characteristic Symbol Notes Rating Unit
Supply Voltage V
BB
20 V
Logic Input Voltage Range V
IN
PWM, SLEW –0.3 to 5.5 V
FC –0.3 to V
BB
V
Logic Output Voltage V
OUT
FG V
BB
V
Output Current I
OUT
Peak (startup and lock rotor) 1.25 A
rms, duty cycle = 100% 900 mA
Operating Ambient Temperature T
A
G temperature range –40 to 105 ºC
Maximum Junction Temperature T
J
(max) 150 ºC
Storage Temperature T
stg
–55 to 150 ºC
Terminal List Table
Name Number Function
CP1 2 Charge pump
CP2 3 Charge pump
CTAP 12 Motor terminal center tap
FC 10 Logic input
FG 8 Speed output signal
GND 5, 11 Ground
OUTA 15 Motor terminal A
OUTB 16 Motor terminal B
OUTC 1 Motor terminal C
PWM 7 Logic input
SENSE 14 Sense resistor connection
SLEW 6 Logic input
TEST 9 Test use only, leave open circuit
VBB 13 Input supply
VCP 4 Charge pump
Selection Guide
Part Number Application Packing
A4941GLPTR-T Commerical/Industrial 4000 pieces per 13-in. reel
A4941GLPTR-A-T Automotive 4000 pieces per 13-in. reel
Thermal Characteristics may require derating at maximum conditions
Characteristic Symbol Test Conditions* Value Unit
Package Thermal Resistance
R
θJA
On 4-layer PCB based on JEDEC standard 34 ºC/W
On 2-layer PCB with 1 in.
2
of copper area each side 52 ºC/W
*Additional thermal information available on the Allegro website
Recommended Operating Conditions
Characteristic Symbol Conditions Min. Typ. Max. Unit
Supply Voltage V
BB
5 – 16 V
Output Current I
OUT
Peak (startup and lock rotor) – – 1 A
Run current – <500 – mA
OUTC
CP1
CP2
VCP
GND
SLEW
PWM
FG
OUTB
OUTA
SENSE
VBB
CTAP
GND
FC
TEST
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
PAD
