MAX14826 Datasheet, PDF (20/32 Pages) Maxim Integrated Products – IO-Link Device Transceiver

MAX14826
IO-Link Device Transceiver
Note that a short negative pulse on IRQ/CQOC and/or
SDO/DOOC will occur at each driver switching event,
even when no loads are driven.
Thermal Protection and Considerations
The internal LDOs and drivers can generate more power
than the package for the devices can safely dissipate.
Ensure that the driver LDO loading is less than the pack-
age can dissipate. Total power dissipation for the device
is calculated using the following equation:
P_TOTAL = P_C/Q + P_DO + P₅ + P_LDO33 + P_Q +
P_CLCQ + P_CLDI
where P_C/Q is the power generated in the C/Q driver, P_DO
is the power dissipated by the DO driver, P₅ and P_LDO33
are the power generated by the LDOs, P_Q is the quies-
cent power generated by the devices.
Ensure that the total power dissipation is less than the
limits listed in the Absolute Maximum Ratings section.
Use the following to calculate the power dissipation (in
mW) due to the C/Q driver:
P_C/Q = [I_C/Q(max)] × [0.5 + 7 × I_C/Q(max)]
Calculate the internal power dissipation of the DO driver
using the following equation:
P_DO = [I_DO(max)] × [0.5 + 7 × I_DO(max)]
Calculate the power dissipation in the 5V LDO, V5, using
the following equation:
P₅ = (V_LDOIN - V₅) × I₅
where I5 includes the ILDO33 current sourced from
LDO33.
Calculate the power dissipated in the 3.3V LDO, LDO33,
using the following equation:
P_LDO33 = 1.7V × I_LDO33
Calculate the quiescent power dissipation in the device
using the following equation:
P_Q = I_CC(max) × V_CC(max)
Thermal Shutdown
All regulators and the C/Q and DO output drivers are
automatically switched off when the internal die tempera-
ture exceeds the +165°C (typ) thermal shutdown thresh-
old. The WU/THSD output asserts low during thermal
shutdown and SPI communication is not available.
Regulators are automatically switched on and WU/THSD
deaaserts when the internal die temperature falls below
the thermal shutdown threshold plus hysteresis. The
internal registers return to their default state when the V₅
regulator is switched on.
Overtemperature Warning (SPI Mode only)
In SPI mode, bits in the Status and Mode registers are
set when the temperature of the device exceeds +127°C
(typ). The OTempInt bit in the Status register is set and
IRQ/CQOC asserts when the OTemp bit in the Mode reg-
ister is set. Read the Status register to clear the OTempInt
bit and IRQ/CQOC.
The OTemp bit is cleared when the die temperature falls
to +104°C.
The device continues to operate normally unless the
die temperature reaches the +165NC thermal shutdown
threshold, when the device enters thermal shutdown.
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