7

of the serial bits as they are shifted out of DO. The fault

action that sets each of the diagnostics bits for each of the 4

switches is described below:

Bit 1 - indicates a thermal overload when the sensed junction

temperature is sensed, the sensor output directly gates-off the

drive to the power output and the respective fault bit is set in

the diagnostic register. When the chip is sufficiently cooled,

the output is gated-on if the input remains ON.

Bit 2 - indicates the fault condition for an output-to-supply short

(shorted load). A small value of resistance (~0.01

Ω) in the

source-to-ground line of the output stage is used to sense the

output short. A comparator senses the voltage level and filters

the output to provide an input to the control stage and to the

diagnostic register. The control state directly shuts down the

output when an over-current condition is sensed. Under this

condition of fault, the input driver is latched off. To restore the

output drive, the short must be removed and the input toggled

OFF and then ON. A short to the supply is the only error

condition that requires an input toggle reset.

Bit 3 - indicates the condition of an output to ground short.

As shown in the Functional Block Diagram, each output

stage has drain-to-supply (VCC1) and drain-to-ground pull-

up and pull-down resistors of approximately 10k

Ω to sense

this condition. When the output is off and the sense level is

low, an output-to-ground short is detected by the

comparator. This condition is sensed when the output is

pulled lower than 0.24xVCC (typical).

Bit 4 - indicates the condition of an open load on the output.

The same divider noted for Bit 3 is used to set the output

level. If the sense level is at or near the mid-range of the

condition, a no-load condition is detected.

Serial Peripheral Interface Bus Control

Technically, the HIP0080 and HIP0081 fault data has only 16

bits. Except for the Error Flag, DF data bit shown in Figure 2,

the format matches that of a normal CPOL = 0, CPHA = 1 SPI

protocol (polarities, phase, etc). The DF bit from the DO output

is active only until the clock starts. The best way to take

advantage of it (if desired) is to connect the DO to the SPI bus,

and also to a port pin, or other logic input. After CS goes low

and before the SPI clocks starts, the DF bit can be read. If it is a

zero, then the rest of the data does not have to be read. (The

data will be all 0’s = no errors). If the DF bit = 1, then the data

must be read to find out which bit(s) is set.

Multiple ICs can be cascaded such that an error bit on any IC

will daisy chain up to the last DO; this allows the microcontroller

to “wire-OR” all of the devices automatically. Other than

bidirectional data IC types, different IC types may be cascaded.

The HIP0080 or HIP0081 should be closest to the

microcontroller to use the DF bit feature. ICs that do not have

an OR’ed means of passing fault bit would require all data be

clocked to check the diagnostic bits.

Clamp Energy Ratings for the HIP0080

and HIP0081

Figures 4 and 5 define the Single Pulse Energy ratings for the

HIP0080 and HIP0081. Refer to Application Note AN9416 for

further information on Single Pulse Energy ratings for inductive

load operation and Dissipation capability for the 15 pin Power

SIP Package. The Device Under Test conducts when the zener

over voltage clamp turns on the output. While drain-to-source

voltage, VDS and drain current, ID are monitored, the current

Single Pulse Energy capability. The energy in Joules is

calculated from the following equation:

Refer to Application Note 9416 for further information on

Single Pulse Energy ratings for inductive load operation

and Dissipation capability for the 15 pin Power SIP

Package.

TABLE 1. SERIAL REGISTER DATA SEQUENCE

CHANNEL NO.

BIT

NO.

FAULT FUNCTION

FAULT

SYMBOL

Switch

Channel 1

1

Over-Temperature

OT1

2

Short to Supply

SB1

3

Short to Ground

SG1

4

Open Load

OI1

Switch

Channel 2

5

Over-Temperature

OT2

6

Short to Supply

SB2

7

Short to Ground

SG2

8

Open Load

OI2

Switch

Channel 3

9

Over-Temperature

OT3

10

Short to Supply

SB3

11

Short to Ground

SG3

12

Open Load

OI3

Switch

Channel 4

13

Over-Temperature

OT4

14

Short to Supply

SB4

15

Short to Ground

SG4

16

Open Load

OI4

HIP0080, HIP0081