L298N

Part: L298 from STMicroelectronics

Type: Dual full-bridge driver

Key Specs:

• Operating supply voltage: up to 46 V
• Total DC current: up to 4 A
• DC operation output current (per channel): 2 A
• Logic supply voltage: 4.5 V to 7 V
• Junction operating temperature: -25 to 130 °C

Features:

• Operating supply voltage up to 46 V
• Total dc current up to 4 A
• Low saturation voltage
• Overtemperature protection
• Logical "0" input voltage up to 1.5 V (high noise immunity)

Applications:

• Dual brush DC motors
• Stepper motors

Package:

• Multiwatt15 V: dimensions not specified
• Multiwatt15 H: dimensions not specified
• PowerSO-20: dimensions not specified

• Operating supply voltage up to 46 V.
• Total dc current up to 4 A.
• Low saturation voltage.
• Overtemperature protection.
• Logical "0" input voltage up to 1.5 V (high noise immunity).

Figure 8 shows a bidirectional DC motor control schematic diagram for which only one bridge is needed.

The external bridge of diodes D1 to D4 is made by four fast recovery elements (trr ≤ 200 ns) that must be chosen of a VF as low as possible at the worst case of the load current.

An external bridge of diodes are required when inductive loads are driven and when the inputs of the IC are chopped; Schottky diodes would be preferred.

The sense output voltage can be used to control the current amplitude by chopping the inputs, or to provide overcurrent protection by switching low the enable input.

The brake function (Fast motor stop) requires that the Absolute Maximum Rating of 2 A must never be exceeded.

When the repetitive peak current needed from the load is higher than 2 A, a paralleled configuration can be chosen (See Figure 9).

This solution can drive up to 3 A in dc operation and until 3.5 A of a repetitive peak current.

On Figure 10 it is shown the driving of a two phase bipolar stepper motor; the needed signals to drive the inputs of the L298 are generated, in this example, by the IC L297.

Figure 11 shows an example of P.C.B. designed for the application of Figure 10.

Figure 12 shows a second two phase bipolar stepper motor control circuit where the current is controlled by the IC L6506.

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Figure 10. Two phase bipolar stepper motor circuit

Note: RS1 = RS2 = 0.5 Ω.

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Figure 12. Two phase bipolar stepper motor control circuit by using the current controller L6506.

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Figure 2. Pin configuration CURRENT SENSING B OUTPUT 4 OUTPUT 3 12 INPUT 4 11 ENABLE B INPUT 3 LOGIC SUPPLY VOLTAGE $V_{SS}$ Multiwatt15 GND INPUT 2 ENABLE A INPUT 1 SUPPLY VOLTAGE $V_S$ OUTPUT 2 OUTPUT 1 CURRENT SENSING A TAB CONNECTED TO PIN 8 D95IN240A GND GND Sense A 19 Sense B N.C. 18 N.C. Out 4 Out 1 17 PowerSO20 Out 2 Out 3 V_s Input 4 Enable B Enable A 13 Input 3 Input 2 12 GND [ 11 GND

Table 3. Pin function

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Table 4. Electrical characteristics

(VS = 42 V; VSS = 5 V, T^j = 25 °C; unless otherwise specified)

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• 1. "Sense A" and "Sense B" pins connected to GND.
• 2. Sensing voltage can be –1 V for t ≤ 50 μsec; in steady state Vsens min ≥ 0.5 V.
• 3. See Figure 4.
• 4. See Figure 6.
• 5. The load must be a pure resistor.

Figure 5. Source current delay times vs. input or enable switching

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Figure 6. Switching times test circuits

Note: For INPUT Switching, set EN = H For ENABLE Switching, set IN = L

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Figure 8. Bidirectional dc motor control

Table 5. Values of bidirectional dc motor control

| Inputs | Function | |---------|--------------|-------------------------| | | C = H; D = L | Forward | | Ven = H | C = L; D = H | Reverse | | | C = D | Fast motor stop | | Ven = L | C = X; D = X | Free running motor stop |

Note: L = Low, H = High, X = Do not care

Figure 9. For higher currents, outputs can be paralleled. Take care to parallel channel 1 with channel 4 and channel 2 with channel 3

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Absolute maximum ratings are those values beyond which damage to the device may occur. These are stress ratings only and functional operation of the device at these conditions is not implied. Operating outside maximum recommended conditions for extended periods of time may impact product reliability and result in device failures.

Table 1. Absolute maximum ratings

Table 2. Thermal data

1. Mounted on aluminum substrate

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