Toshiba Launches Motor Driver IC

The TC78H660FNG runs off input supply voltages of 2.5 to 16 volts can deliver a maximum PWM-controlled current of 2 amps. The IC, based on the company’s double-diffused MOSFET (DMOS) process,  is Toshiba’s latest addition to its lines of drivers for stepper and brushed DC motors

 

The TC78H660FNG. Image courtesy of Toshiba

 

Very Low “ON” Resistance

Under the typical operating conditions, the TC78H660FNG features an on-resistance of only 0.48Ω,   saving energy. It also means that less heat is generated, which, in turn, would have to be dissipated, saving space and costs.

 

What is an H-Bridge Motor Driver?

An H-bridge is a simple circuit used to channel current through a load; typically an inductive load, such as a motor. It consists of four FETs, often with only two turned on at one time. It is often used to reverse the rotational direction of a DC motor. 

 

Image courtesy of All About Circuits

 

In the image above, if Q1 and Q4 are both turned on, the left terminal of the motor is connected to the battery and the right terminal is connected to ground. Alternatively, if Q3 and Q2 are turned on, it’s the right side that is connected to the battery, and the left side to ground.

 

Four Function Modes

• Clockwise (CW)
• Counter Clockwise (CCW)
• Short Brake
• Stop

 

Important Features of the TC78H660FNG

• Built-in Dual H Bridge
• Constant current control or direct PWM control with no need for a current sense resistor 
• Built-in VCC regulator for internal circuitry
• Chopping frequency of a motor can be adjusted by external resistor
• Selectable motor modes include forward, reverse, stop and brake
• Standby current is 0.1μA or less 

 

Block diagram of the TC78H660FNG. Image courtesy of Data Sheet 

 

IN Input Mode and PHASE Input Mode

After exiting standby mode, IN input mode and PHASE input mode are selectable via the MODE pin.

 

IN input Mode (Mode Pin is at logic low)

Standby	IN1A	IN2A	IN1B	IN2B	Mode
H	H	H	H	H	Short Brake
H	H	L	Don’t Care	Don’t Care	Forward
H	L	H	Don’t Care	Don’t Care	Reverse
H	Don’t Care	Don’t Care	H	L	Forward
H	Don’t Care	Don’t Care	L	H	Reverse
H	L	L	L	L	Stop
L	Don’t Care	Don’t Care	Don’t Care	Don’t Care	Standby

 

PHASE Input Mode (Mode Pin is at logic high)

Standby	Phase A	Enable A	Phase B	Enable B	Mode
H	H	H	Don’t Care	Don’t Care	Forward
H	L	H	Don’t Care	Don’t Care	Reverse
H	Don’t Care	Don’t Care	H	H	Forward
H	Don’t Care	Don’t Care	L	H	Reverse
H	Don’t Care	L	Don’t Care	L	Stop
L	Don’t Care	Don’t Care	Don’t Care	Don’t Care	Standby

 

Safety Functions

• Safety functions include thermal shut down, under voltage lockout and over current detection
• Flag output function for thermal shut down and over current detection

 

Applications

• Mobile devices running off a 3.7 volt lithium ion batteries
• 5 volt USB-powered equipment
• 12 volt system devices 
• Smart meters
• Refrigerators

 

Physical and Environmental Specifics

• The TC78H660FNG is available in a 5 by 6.4 by 1.2 mm TSSOP16 package with a standard pin-assignment. 
• Typical weight is 56.5 mg
• RoHS compatibility is available
• The unit operates over a temperature range of -40 to +85 ℃