ADP1048DC1-EVALZ Analog Devices, ADP1048DC1-EVALZ Datasheet - Page 12

• Manufacturer Part Number: ADP1048DC1-EVALZ
• Description: Daughter Cards & OEM Boards ADP1048 DAUGHTERCARD
• Manufacturer: Analog Devices
• Series: ADP1048r

Specifications of ADP1048DC1-EVALZ

• Rohs: yes
• Product: Daughter Cards
• Description/function: 100 kHz daughter board
• Dimensions: 40 mm x 25 mm
• Interface Type: I2C
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Operating Supply Voltage: 3.3 V
• Factory Pack Quantity: 1
• For Use With: ADP1048

ADP1047/ADP1048
CONTROLLER ARCHITECTURE
The
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This section describes the internal architecture of the chip.
CURRENT SENSE
Current sensing is used for the control, protection, and monitor-
ing of the PFC stage. For normal operation, the power factor
correction control loop requires inductor current information.
The typical implementation uses a sense resistor on the input
bus. A combination of two current transformers in series with
the power switch and the boost diode can be used to reconstruct
the inductor current and minimize losses in the resistive shunt,
but, in general, a good quality shunt resistor provides much
better accuracy in measuring input current and input power.
The inputs to the current sense ADC are differential. A pair of
matched current sources is provided to level shift the negative
signal across the current sense element in the input range of the
current sense ADC (see Figure 7).
The current sense can be calibrated digitally to remove any
errors due to external components (see the Current Sense Gain
and Offset Trim section). This calibration can be performed in
the production environment; the settings are saved in the
EEPROM of the ADP1047/ADP1048.
ADP1047/ADP1048
Power factor correction control loop (see the Power Factor
Correction Control Loop section)
Advanced input power metering (see the Advanced Input
Power Metering section)
PMBus digital communication (see the PMBus Digital
Communication section)
10kΩ
CS–
Figure 7. Current Sense Configuration
VDD
I
L
integrate the following functions:
10kΩ
CS+
ADP1047/ADP1048
+
–
ADC
11-BIT
Rev. 0 | Page 12 of 84
The output of the Σ-Δ ADC is used for the following purposes:
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RMS INPUT OVERCURRENT PROTECTION
The
(OCP). RMS OCP (or accurate OCP) is distinct from the instan-
taneous pulse-by-pulse fast overcurrent protection and is based
on the rms value of the input ac current.
The measured value is compared to the limit set in the
IIN_OC_FAULT_LIMIT register (Register 0x5B) at the
end of each half cycle of the ac line. If the limit is exceeded,
the action programmed in the IIN_OC_FAULT_RESPONSE
register (Register 0x5C) is triggered.
In addition, an input current warning limit can be programmed
in the IIN_OC_WARN_LIMIT register (Register 0x5D). This
warning limit has no action attached to it, but it sets flags in the
STATUS_BYTE register (Register 0x78, Bit 0), the STATUS_WORD
register (Register 0x79, Bit 13), and the STATUS_INPUT register
(Register 0x7C, Bit 1).
FAST OVERCURRENT PROTECTION (ILIM PIN)
A dedicated current limiting pin (ILIM) is provided to protect
the part from pulse-by-pulse overcurrent events. When the
threshold is crossed, the PWM pulse is terminated. This action
is independent of any programming of the fast OCP flag. The
next switching cycle resumes normally. Additional actions can
be programmed (see Table 5).
The OCP comparator on the ILIM pin can accept positive or
negative signals; the pin is referred to PGND (power ground) and
has programmable level shifting current sources (see Table 5).
These sources can be changed during normal operation to adapt
to the level at which the overcurrent protection is triggered.
The OCP comparator also features programmable blanking and
debounce times (see Table 5). If OCP is triggered, the PWM
signal is terminated and operation resumes at the next switch-
ing cycle unless a different action is specified for the fast OCP
response in Register 0xFE00.
ADP1047/ADP1048
The output is decimated at the switching frequency for the
control loop. The effective number of bits (ENOB) is >7
when the current loop bandwidth is 10 kHz; the ENOB
is >10 when the current loop bandwidth is 1 kHz.
The 11-bit result is calculated and updated at each half line
cycle for high accuracy ac line current and input power
monitoring and for overcurrent protection (accurate OCP).
provide rms overcurrent protection
Data Sheet