L-ASC10
In-System Programmable
Hardware Management Expander
2
Description
The L-ASC10 (Analog Sense and Control - 10 rail) is a
Hardware Management (Power, Thermal, and Control
Plane Management) Expander designed to be used with
Platform Manager 2, MachXO2, MachXO3, or ECP5
FPGAs to implement the Hardware Management Control
function in a circuit board. The L-ASC10 (referred to as
ASC) enables seamless scaling of power supply voltage
and current monitoring, temperature monitoring, sequence
and margin control channels. The ASC includes dedicated
interfaces supporting the exchange of monitor signal status
and output control signals with these centralized hardware
management controllers. Up to eight ASC devices can be
used to implement a hardware management system.
The ASC provides three types of analog sense channels:
voltage (nine standard channels and one high voltage chan-
nel), current (one standard voltage and one high voltage),
and temperature (two external and one internal) as shown
in Figure 2.
Each of the analog sense channels is monitored through
two independently programmable comparators to support
both high/low and in-bounds/out-of-bounds (window-com-
pare) monitor functions. The current sense channels feature
a programmable gain amplifier and a fast fault detect (<1 µs
response time) for detecting short circuit events. The tem-
perature sense channels can be configured to work with dif-
ferent external transistor or diode configurations.
Nine general purpose 5 V tolerant open-drain digital input/
output pins are provided that can be used in a system for
controlling DC-DC converters, low-drop-out regulators
(LDOs) and optocouplers, as well as for supervisory and
general purpose logic interface functions. Four high-voltage
charge pumped outputs (HVOUT1-HVOUT4) may be con-
figured as high-voltage MOSFET drivers to control high-side
MOSFET switches. These HVOUT outputs can also be pro-
grammed as static output signals or as switched outputs (to
support external charge pump implementation) operating at
a dedicated duty cycle and frequency.
The ASC device incorporates four TRIM outputs for control-
ling the output voltages of DC-DC converters. Each power
supply output voltage can be maintained typically within
0.5% tolerance across various load conditions using the
Digital Closed Loop Control mode.
The internal 10-bit A/D converter can be used to monitor the
voltage and current through the I2C bus. The ADC is also
used in the digital closed loop control mode of the trimming
block.
The ASC also provides the capability of logging up to 16
status records into the on-chip nonvolatile EEPROM mem-
ory. Each record includes voltage, current and temperature
monitor signals along with digital input and output levels.
The dedicated ASC Interface (ASC-I/F) is a reliable serial
channel used to communicate with a Platform Manager 2,
MachXO2, MachXO3, or ECP5 FPGA in a scalable star
topology. The centralized control algorithm in the FPGA
monitors signal status and controls output behavior via this
ASC-I/F. The ASC I2C interface is used by the FPGA or an
external microcontroller for ASC background programming,
interface configuration, and additional data transfer such as
parameter measurement or I/O control or status. For exam-
ple, voltage trim targets can be set over the I2C bus and
measured voltage, current, or temperature values can be
read over the I2C bus.
The ASC also includes an on-chip output control block
(OCB) which allows certain alarms and control signals a
direct connection to the GPIOs or HVOUTs, bypassing the
ASC-I/F for a faster response. The OCB is used to connect
the fast current fault detect signal to an FPGA input directly.
It also supports functions like Hot Swap with a programma-
ble hysteretic controller.
ASC Block Diagram
Figure 2. ASC Block Diagram
Output Control
Block
ASC
Interface
(ASC-I/F)
Non -
Volatile
Fault Log
Trim & Margin
Control
ADC
ADC
MOSFET &
Digital I/O Drive
Current
Sense
Voltage
Sense
Temperature
Sense
I
2
C
Interface
C