Power Manager II
Hercules Development Kit
Power Manager II Hercules Demos:
• Default State – With demo DIP switches set as shown (all 0’s) the LCD will cycle through its self-
test sequence along with the PLD output LEDs. This is the default (shipped) turn-on condition.
• Demo 1: Switching Power Supply Trim – The Power Manager II Trim-DAC output trims the
1.2V supply to better than 1% of its factory set value. This is done by the ispPAC
®
-POWR1220AT8
and MachXO™ using an external closed loop trim to adjust the feedback into the regulator trim
pin. The LCD displays the output voltage of the 1.2V switching regulator at VMON1 using the
ADC in the POWR1220AT8. Pressing and holding down the mode (SW3) switch changes the trim
mode from closed loop to open loop. In this mode, the Trim-DAC output is set to a fixed (stored)
digital value which is selected by the Voltage Profile Select pins of the Power Manager II.
• Demo 2: Power Supply Margin Down – With demo DIP switches set as shown, the supply is
trimmed to -7.5% of its factory value (1.2V - 0.09V = 1.11V) using closed loop trim. VMON1 is
chosen to measure the 1.2V DC-DC power supply and the value is read by the POWR1220AT8
ADC and displayed on the LCD. Pressing the mode switch results in the trim mode switching
from closed loop to open loop trim. This means the output is set to a fixed (stored) digital value
and will not be as accurate as closed loop trim.
• Demo 2a: Power Supply Margin Up – With demo DIP switches set as shown, the supply is
trimmed to +7.5% of its factory value (1.2V + 0.09V = 1.29V) using closed loop trim. VMON1
is chosen to measure the 1.2V DC-DC power supply and the value is read by the POWR1220AT8
ADC and displayed on the LCD. Pressing the mode switch results in the trim mode switching
from closed loop to open loop trim. This means the output is set to a fixed (stored) digital value
and will not be as accurate as closed loop trim.
• Demo 3: 12V Voltage – This is a POWR1220AT8-enabled version of the input 12V. The input
12V can come from the 12V wall plug input or an external source. This voltage exceeds VMON’s
6V maximum input limit. An intermediate voltage is created by dividing by a 4:1 resistor divider
network. The intermediate voltage is read at VMON11 and applied to the internal ADC for mea-
surement. The measured value is then digitally multiplied by 4 and displayed on the LCD.
• Demo 4: Power Supply Fault Monitoring – The slider potentiometer simulates an over/under
voltage condition on a 2.5V power supply and is monitored by VMON9. The full range of voltage
is 0V to 3.25V. The LCD displays the voltage. VMON9 is configured in the Power Manager II
in “window” mode with a lower trip point of 0.75V and an upper trip point of 2.25V. When the
voltage at VMON9 is above the upper or below the lower trip point a fault is detected by the
Power Manager II. These faults are detected and counted for readout in Demo 4a. Cycling board
power will also result in a fault being recorded. Note: These faults were not programmed to cause
a PWR_GOOD failure.
• Demo 4a: Fault Logging – The LCD displays the total count of faults recorded by the Power
Manager II and MachXO. Pressing the mode switch (SW3) clears all the recorded faults. Faults
are detected by the Power Manager II when the slider potentiometer is outside the window limits
(see Demo 4) or when power is removed from the board.
• Demos 5 and 5a: VID Voltage – The Trim-DAC output of the Power Manager II is used to step
the 1.2V DC-DC supply based on the value of the VID-DIP switches. Switches 3-0 provide a
4-bit unsigned binary value ranging from 0-15. This value is multiplied by 10mV and added to,
or subtracted from, the nominal 1.2V based on the polarity of demo DIP switch 4. For example,
0000b=0*10mV=0V, 0100b=4*10mV=40mV, 1000b=8*10mV=80mV; 1100b=12*10mV=120mV.
This procedure is continued on the next page.
