ADP3208 ON Semiconductor, ADP3208 Datasheet - Page 24

• Manufacturer Part Number: ADP3208
• Description: 7-bit, Programmable, Dual-phase, Mobile, Cpu, Synchronous Buck Controller
• Manufacturer: ON Semiconductor

ADP3208
The internal VRTT comparator has a hysteresis of approximately
100 mV to prevent high frequency oscillation of VRTT when
the temperature approaches the set alarm point.
POWER MONITOR FUNCTION
The ADP3208 includes a power monitor. The circuit creates the
product of the output voltage and the output current. The
multiplication is done by converting the differential current
sense signal from CSCOMP to CSREF into a pulse-modulated
periodic signal stream and then scaling that signal with the
output voltage. The duty cycle of the pulse-modulated PMON
signal is proportional to the current, and the amplitude is
proportional to the voltage. The maximum load current that
corresponds to the full-scale (100%) modulated signal can be
adjusted by a resistor, R
R
RC low-pass filter connected to the PMON output demodulates
the PWM pulse stream and creates averaged output current or
power information, depending on which rail the open-drain
PMON output is pulled up to.
If PMON is pulled up to a dc voltage, the RC-filtered voltage is
proportional to the averaged load current. Figure 37 shows the
PMON configuration used to monitor load current.
PMONFS
also affects the clock frequency of the PWM circuit. An
PMONFS
, tied from PMONFS to GND.
Rev. 1 | Page 24 of 38 | www.onsemi.com
If PMON is pulled up to the converter output node, the
demodulated voltage becomes proportional to the averaged
power (see Figure 38).
Figure 37. PMON Current Monitor Configuration
Figure 38. PMON Power Monitor Configuration
PMON
PMON
PWM
PWM
ADP3208
ADP3208
PMONFS
PMONFS
PMON
PMON
13
14
13
14
VOLTAGE
V
CORE
R
R
DC
PMONFS
PMONFS
R
R
R
R
PULL UP
PULL UP
FILTER
FILTER
C
C
FILTER
FILTER
CURRENT
SIGNAL
POWER
SIGNAL