Datasheet
Data Sheet ADP1053
Rev. A | Page 25 of 84
POWER MONITORING AND FLAGS
The ADP1053 has extensive system and fault monitoring
capabilities for the sensed signals. The system monitoring
functions include voltage, current, power, and temperature
readings. The fault conditions include out-of-limit values for
current, voltage, power, and temperature. The limits for the
fault conditions are programmable.
The ADP1053 has an extensive set of flags that are set when
certain thresholds or limits are reached. For information about
the thresholds and limits, see the Flag Registers section.
MONITORING FUNCTIONS
The ADP1053 monitors and reports several signals, including
voltages, currents, power, and temperature. All these values
are stored in individual registers and can be read through the
PMBus/I
2
C interface.
The accuracy of the ADP1053 is specified relative to the full-
scale range (FSR) of the signal that is measured.
VOLTAGE READINGS
VS_A and VS_B Readings
The VS_A and VS_B voltage value registers (Register 0xFED5
and Register 0xFED6, respectively) are updated every 10 ms.
The VS_A and VS_B ADCs have an input range of 0 V to 1.6 V
and a resolution of 12 bits, which means that the LSB size is
1.6 V/4096 = 390.6 µV. The valid input range is 1.5 V, which
means that the maximum ADC output code is limited to
1.5 V/390.6 µV = 3840.
The equation to calculate the ADC code at a specified voltage
(V
X
) is given by the following formula:
ADC CODE = V
X
/390.6 µV
For example, when there is 1 V on the input of the VS_A ADC,
VS_A ADC CODE = 1 V/390.6 µV = 2560
ACSNS Readings
The ACSNS voltage value register (Register 0xFED9) is updated
every 1 ms. The ACSNS ADC has an input range of 0 V to 1.6 V
and a resolution of 11 bits, which means that the LSB size is 1.6 V/
2048 = 781.25 µV. The valid input range is 1.4 V, which means
that the ADC output code is limited to 1.4 V/781.25 µV = 1792.
The equation to calculate the ADC code at a specified voltage
(V
X
) is given by the following formula:
ADC CODE = V
X
/781.25 µV
For example, when there is 1 V on the input of the ACSNS ADC,
ACSNS ADC CODE = 1 V/781.25 µV = 1280
CURRENT READINGS
By default, the current reading ADCs are updated every 10 ms.
However, Register 0xFE89 can be used to change the update rate
to 50 ms, 100 ms, or 200 ms.
CS and CS1 (CS1_A/CS1_B) Readings
The CS, CS1_A, and CS1_B value registers (Register 0xFED0,
Register 0xFED1, and Register 0xFED2, respectively) are updated
every 10 ms. The CS, CS1_A, and CS1_B ADCs have an input
range of 0 V to 1.6 V and a resolution of 12 bits, which means
that the LSB size is 1.6 V/4096 = 390.6 µV.
The equation to calculate the ADC code at a specified voltage
(V
X
) is given by the following formula:
ADC CODE = V
X
/390.6 µV
For example, when there is 1 V on the input of the CS ADC,
CS ADC CODE = 1 V/390.6 µV = 2560
CS2 (CS2_A/CS2_B) Readings
The CS2_A and CS2_B value registers (Register 0xFED3 and
Register 0xFED4, respectively) are updated every 10 ms. The
CS2_A and CS2_B ADCs have an input range of 0 mV to 120 mV
and a resolution of 12 bits, which means that the LSB size is
120 mV/4096 = 29.3 µV.
The equation to calculate the ADC code at a specified voltage
(V
X
) is given by the following formula:
ADC CODE = V
X
× 4096/Sensing Range
For example, when there is 40 mV on the input of the CS2_A
ADC and the sensing range is 120 mV,
CS2_A ADC CODE = 40 mV × 4096/120 mV = 1365
TEMPERATURE READINGS (RTD1 AND RTD2 PINS)
The RTD1 and RTD2 pins are provided for use with an external
100 kΩ NTC thermistor. An internal current source of 10 µA,
20 µA, 30 µA, or 40 µA can be selected. Therefore, with a
100 kΩ thermistor, the voltage on the RTDx pin is 1 V at 25°C.
An ADC on the ADP1053 monitors the voltage on each RTDx
pin. The ADC has a 1 kHz bandwidth and 12-bit resolution.
The ADC reading is used for overtemperature protection and
monitoring. For more information, see the Overtemperature
Protection (OTP) and Overtemperature Warning (OTW) Flags
section and the Temperature Linearization Scheme section.
ADP1053
ADC
ADC
OTP1
OTP2
THRESHOLD
THRESHOLD
RTD
TEMPERATURE
REGISTERS
NTC
100kΩ
NTC
100kΩ
RTD1
RTD2
10241-022
Figure 23. RTD Pin Internal Details