Single LNB Supply and Control Voltage Regulator

A8290

16

Allegro MicroSystems, Inc.

115 Northeast Cutoff, Box 15036

Worcester, Massachusetts 01615-0036 (508) 853-5000

www.allegromicro.com

Table 6. Status Register 1

Bit

Name

Function

0

DIS

LNB output disabled

1

–

Not Used

2

OCP

Overcurrent

3

–

Not Used

4

PNG

Power Not Good

5

–

Not Used

6

TSD

Thermal Shutdown

7

VUV

Bit 0

DIS

LNB Output Disabled. DIS is used to indicate the current condition of the LNB

output. At power-on, or if a fault condition occurs, DIS will be set. This bit changing

to 1 does not cause the IRQ to activate because the LNB output may be disabled in-

if the LNB output is enabled.

Bit 1

–

Not used.

Bit 2

OCP

Overcurrent. If the LNB output detects an overcurrent condition, for greater than

48 ms, the LNB output will be disabled. The OCP bit will be set to indicate that an

overcurrent has occurred and the disable bit, DIS, will be set. The Status register is

OCP bit is reset in all cases, allowing the master to reenable the LNB output.

Bit 3

–

Not used.

Bit 4

PNG

Power Not Good. Set to 1 when the LNB voltage is below 85% of the programmed

voltage. The PNG bit is reset when the LNB voltage is within 90% of the pro-

grammed LNB voltage. PNG is always active so, if the LNB output is disabled, then

PNG will be a logic 1. At power-up, PNG reports a logic 1 until the LNB output is

enabled and within 90% of the programmed LNB voltage.

Bit 5

–

Not used.

Bit 6

TSD

Thermal shutdown. 1 indicates that the A8290 has detected an overtemperature

condition and has disabled the LNB output. The disable bit, DIS, will also be set.

clock pulse in the data read sequence. If the condition is no longer present, then the

TSD bit will be reset, allowing the master to reenable the LNB output if required. If

the condition is still present, then the TSD bit will remain at 1.

Bit 7

VUV

Undervoltage Lockout. 1 indicates that the A8290 has detected that the input sup-

occurred disabling the LNB outputs. The disable bit, DIS, will also be set and the

A8290 will not reenable the output until so instructed by writing the relevant bit into

the control registers. The status of the undervoltage condition is sampled on the rising

present, then the VUV bit will be reset allowing the master to reenable the LNB out-

put if required. If the condition is still present, then the VUV bit will remain at 1.