SLVS855K July   2008  – March 2021

PRODUCTION DATA

1. Features
2. Applications
3. Description
4. Revision History
5. Pin Configuration and Functions
6. Specifications
7. Parameter Measurement Information
8. Detailed Description
1. 8.1 Overview
2. 8.2 Functional Block Diagrams
3. 8.3 Feature Description
4. 8.4 Device Functional Modes
1. 8.4.1 Device Operation
1. 8.4.1.1 Slow-Decay SR (Brake Mode)
2. 8.4.1.2 Fast Decay With Synchronous Rectification
9. Application and Implementation
1. 9.1 Application Information
2. 9.2 Typical Application
1. 9.2.1 Design Requirements
2. 9.2.2 Detailed Design Procedure
3. 9.2.3 Pulse-Width Modulating
4. 9.2.4 Application Curves
3. 9.3 Parallel Configuration
10. 10Power Supply Recommendations
11. 11Layout
12. 12Device and Documentation Support
13. 13Mechanical, Packaging, and Orderable Information

• PWP|16
• RTY|16
• PWP|16
• RTY|16

#### 9.3.4.4 Maximum System Current

The idea behind placing multiple DRV8800/01 devices in parallel is to increase maximum drive current. At first glance, it may seem that the new increased ITRIP setting is given by Equation 8.

Equation 8.

Where:

N is the number of DRV8800/01 devices connected in parallel.

ITRIP is the individual ITRIP value per device.

However, although in theory accurate, due to tolerances in internal SENSE amplifier/comparator circuitry, the system ITRIP should be expected to be less than the addition of all the individual ITRIP. The reason for this is that as soon as one of the devices senses a current for which the H Bridge should be disabled, the remaining devices will end up having to conduct the same current but with less capacity. Therefore, remaining devices are expected to get disabled shortly after.

A good rule of thumb is to expect 90% of the theoretical maximum.

By way of example, if the system level requirements indicate that 6 A of current are required to meet the motion control requirements, then:

6 A = (2.8 A x 0.9)N

N = (6 A) / (2.8 A x 0.9)

N = 2.38

In this example, three DRV8800/01 devices would be required to meet the safety needs of the system.