NJM2646M-TE1 NJR, NJM2646M-TE1 Datasheet - Page 6

• Manufacturer Part Number: NJM2646M-TE1
• Description: Motor / Motion / Ignition Controllers & Drivers 2-Phase DC Brushless Motor Pre-driver IC
• Manufacturer: NJR
• Type: 2 Phase DC Brushless Motor Driverr

Specifications of NJM2646M-TE1

• Operating Supply Voltage: 4 V to 15 V
• Supply Current: 10.5 mA
• Mounting Style: SMD/SMT
• Package / Case: DMP-8
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

NJM2646
3.Design of hall element bias resistance (R1 and R2)
- 6 -
constant start up must be confirmed in actual evaluation taking operating variations (i.e. Temperature, Voltage change
and so on) in consideration.
Ct Teminal voltage
R
R
LATeminal voltage
1
1
Auto Resume Time (Toff) is given by:
Where C2 is 0.47uF:
In actual application, Lock detection time (Ton) is affected by the mechanical time constant of a motor. Therefore,
A typical value of C2 is either 0.47uF or 1uF depending on a motor.
Lock Protection
the picture below.
Lock Alert Out (LA: Pin 3) is a open collector output and R3 is a pull up resister. A typical value of R3 is 10k .
It must be noted that Lock Alert Out stays a H state during few hundred milliseconds from power up as shown in
Non-excitation hall bias voltage is to be set at a half of VCC for effective use of common-mode input voltage range.
Therefore the same value of hall bias resistors is selected for R1 and R2.
Given that the bias current is set to be 5mA by HW101A datasheet, R1 and R2 can be determined as follows:
Hall amplifier is a differential amplifier with hysteresis characteristics (24mV typical).
The common-mode input voltage is between 1.5V and Vcc-2V and the input signal must be within the range.
Motor output
R
R
T
OFF
2
Hall input
2
T
OFF
1
Ihbias
Vcc
2 .
C
k
2
. 0
Vch
47
Idc
5
10
Vcl
12
10
6
sec
3
2
0
LA terminal output
5 .
4 .
2
Power supply
4 .
10
. 0
k
95
Motor Locked
6
. 1
82
t
on
sec
High
Hundreds of millimeter second
Motor Lock protection period
t
OFF
Returns to normal operation