NJM2640E-TE1 NJR, NJM2640E-TE1 Datasheet - Page 6

• Manufacturer Part Number: NJM2640E-TE1
• Description: Motor / Motion / Ignition Controllers & Drivers 2-Phase DC Brushless Motor Pre-Driver IC
• Manufacturer: NJR
• Type: Two Phase Unipolar DC Brushless Motor Pre-Driver ICr

Specifications of NJM2640E-TE1

• Product: Stepper Motor Controllers / Drivers
• Operating Supply Voltage: 4 V to 55 V
• Supply Current: 3 mA to 4 mA
• Mounting Style: SMD/SMT
• Package / Case: EMP-8
• Operating Temperature: - 40 C to + 85 C
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

NJM2640
3. Design of hall element bias resistance (R1 and R2)
4. Design of Power Transistor base resistance (R4 and R5)
5. Design of spike killer for power transistor (ZD1 and ZD2)
- 6 -
6mA.
noise (often called as Echo noise) during operation.
determine the value with actual application for better noise performance.
generated when power transistors is (TR1 and TR2) turned off from on.
elements.
range.
voltage range. Therefore the same value of hall bias resistors is selected for R1 and R2.
follows:
efficiency can be obtained.
HFE of 2SD0968A (NEC) is 50 from its datasheet. Given that Io is 300mA, the base current of TR1 is
R4 is given by:
Where; VCC is 48V, VCE of NJM2640 is 1.5V, VBE of TR1 is 0.7V
The pull down resistance R5 (connected to TR1) influences turn-off time of TR1.
Faster Turn-off time of TR1 reduces peak current of motor wining current resulting in lower echo fan
A typical R5 value is ranging from 1k to 10k . As explained the above, it is highly recommended to
Zenner diodes (often referred as spike killer ) are used for limiting kick back voltage of motor winding
The output voltage of hall elements is influenced by the bias current and magnetic flux density of hall
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
Non-excitation hall bias voltage is to be set at a half of VCC for effective use of common-mode input
Given that the bias current is set to be 5mA by HW101A datasheet, R1 and R2 can be determined as
The optimum input voltage of NJM2640 is 100mVp-p and higher. With such input voltage, the highest
Motor Winding Current
R
R
R
R
1
1
4
4
R
R
2
VCC
2
48
6
Ihbias
4
0
Vcc
8 .
10
7 .
VBE
k
IB
3
1
5 .
5
VCE
. 7
48
10
63
3
10
9
3
6 .
k
7
6 .
Peak current becomes small early the turnoff the TR1
k