Datasheet

MAX14821
IO-Link Device Transceiver
25Maxim Integrated
Mode Register [R1, R0] = [1,1]
Bit D7 D6 D5 D4 D3 D2 D1 D0
Bit Name
RST WuIntEn DoFault C/QFault UV24 OTemp UV33En LDO33Dis
Read/Write
R/W R/W R R R R R R/W
POR State
0 0 0 0 0 0 0 0
Use the Mode register to reset the MAX14821 and manage the 3.3V LDO. The Mode register has bits that repre-
sent the current status of fault conditions. When writing to the Mode register, the contents of the fault indication bits
(bits 2 to 5) do not change.
BIT NAME DESCRIPTION
D7 RST Register Reset. Set RST to 1 to reset all registers to their default power-up state. Then
set RST to 0 for normal operation.
The Status register is cleared and IRQ deasserts (if asserted) when RST = 1. Interrupts
are not generated while RST = 1.
D6 WuIntEn Wake-Up Interrupt Enable. Set WuIntEn to 1 to enable wake-up interrupt generation.
When WuIntEn is set, the WuInt bit in the Status register is set and IRQ asserts when
a valid wake-up condition is detected. The C/Q driver must be enabled for wake-up
detection. The state of WuIntEn does not affect the WU output. See the Wake-Up
Detection section for more information.
D5 DoFault DO Fault Status. The DoFault bit is set when a short circuit or voltage fault occurs at
the DO driver output (see the DO Fault Detection section for more information). The
DoFault and DoFaultInt bits are both set when a fault occurs on DO. DoFault is cleared
when the fault is removed.
D4 C/QFault C/Q Fault Status. The C/QFault bit is set when a short circuit or voltage fault occurs at
the C/Q driver output (see the C/Q Fault Detection section for more information). The
C/QFault and C/QFaultInt bits are both set when a fault occurs on C/Q. C/QFault is
cleared when the fault is removed.
D3 UV24 V
CC
Undervoltage Condition. Both the UV24 and the UV24Int bits are set when V
CC
falls below V
CCUVLO
. UV24 is cleared when V
CC
rises above the V
CC
threshold. V
5
must be present for V
CC
undervoltage monitoring.
D2 OTemp Temperature Warning. The OTemp bit is set when a high-temperature condition
occurs on the device. Both the OTempInt interrupt in the Status register and the OTemp
bit are set when the junction temperature of the die rises to above +115NC (typ). The
OTemp bit is cleared when the junction temperature falls below +95NC (typ).
D1 UV33En LDO33 UV Enable. Set the UV33En bit to 1 to assert the UV output when LDO33 volt-
age falls below the 2.4V (typ) undervoltage-lockout threshold. The UV33En bit does
not affect the UV33Int bit in the Status register; IRQ asserts when V
LDO33
falls below
V
LDO33UVLO
regardless of the state of UV33En.
D0 LDO33Dis LDO33 Enable/Disable. Set LDO33Dis to 1 to disable the 3.3V linear regulator (LDO33).