FMS7401 Datasheet, PDF (29/80 Pages) Fairchild Semiconductor – Digital Power Controller

PRODUCT SPECIFICATION
FMS7401/7401L
Bit 6 of the ADCNTRL2 register is the Programmable Comparator non-inverting input selection (COMPSEL) bit.¹ If
COMPSEL=0, the non-inverting input of the Programmable Comparator is the G4/AIN0 device pin. If COMPSEL=1, the non-
inverting input of the Programmable Comparator is the G2/AIN2 device pin. Before enabling the Programmable Comparator
circuit, the selected analog input port pin must be configured as a tri-state input bypassing the I/O circuitry.²
Bit 1 of the Comparator Control (COMP) register is the Programmable Comparator circuit’s voltage loop (VLOOP) configura-
tion enable bit. If VLOOP=0, the Programmable Comparator circuit is configured to compare the analog G4/AIN0 or G2/AIN2
input (COMPSEL=0 or 1) to one of the 63 voltage threshold levels. If VLOOP=1, enables the voltage loop configuration where
the analog G4/AIN0 or G2/AIN2 input (COMPSEL=0 or 1) to the Uncommitted (Error) Amplifier output (AOUT).
Bit 7 of the Digital Delay (DDELAY) register is the Programmable Comparator circuit enable (COMPEN) bit. If COMPEN=0,
the Programmable Comparator circuit is disabled and the COUT signal is low. If COMPEN=1, the Programmable Comparator
circuit is enabled and the COUT signal generated by the comparison of the two inputs.
Bit 0 (COUT) of the Comparator Control (COMP) register is the latched comparator output (COUT) signal. If the Programma-
ble Comparator circuit is enabled, the COUT signal is latched by the main system instruction (FICLK) clock into the COUT bit of
the COMP register. Software may only read the COUT bit to monitor the comparator’s activity. The COUT bit cannot cause
any microcontroller hardware interrupt or any other actions.
Figure 9. Programmable Comparator Block Diagram (VLOOP = 1)
DDELAY
Register
EPWM DD[3] DD[2] DD[1] DD[0]
5
3
2
1
0
G2/AIN2
G4/AIN0
G7/A_OUT
G6/-A_IN
COMPSEL
(ADCNTRL2[6])
F_RCLK2
En _{DIGITAL DELAY}
CIRCUIT
Uncommitted (Error)
Amplifier
_
+
V_REF
VLOOP
0.23R
R
Comparator
+
_
COMP Register
Programmable
Reference
ACH5
PWMOFF (WKEN[6])
COUT
REV. 1.0.2 6/23/04
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