afs600 Actel Corporation, afs600 Datasheet - Page 98

• Manufacturer Part Number: afs600
• Description: Actel Fusion Programmable System Chips Mixed-signal Family With Optional Arm Support
• Manufacturer: Actel Corporation

Gate Driver
The Fusion Analog Quad includes a Gate Driver
connected to the Quad's AG pin
to work with external p- or n-channel MOSFETs, the Gate
driver is a configurable current sink or source and
requires an external pull-up or pull-down resistor. The
AG supports 4 selectable gate drive levels: 1 µA, 3 µA,
10 µA, and 30 µA
supports a High Current Drive mode in which it can sink
20 mA; in this mode the switching rate is approximately
1.3 MHz with 100 ns turn-on time and 600 ns turn-off
Figure 2-74 • Gate Driver
The gate-to-source voltage (V
is limited to the programmable drive current times the
external pull-up or pull-down resistor value
2 -8 4
Actel Fusion Programmable System Chips
V
Off-Chip
On-Chip
gs
Pads
≤ I
g
× (R
Power
pullup
AV
Digital
(Figure 2-75 on page
Prescaler
Input
or R
Monitor Block
Voltage
pulldown
(DAVOUTx)
Line Side
To FPGA
To Analog MUX
gs
)
) of the external MOSFET
(Figure
2-85). The AG also
Monitor / Instr
AC
2-74). Designed
Amplifier
Digital
Prescaler
Current
Input
(EQ
Monitor Block
2-4).
(DACOUTx)
Current
To FPGA
Analog Quad
EQ 2-4
A d v a n c e d v 1 . 4
To Analog MUX
R
pullup
time. Modeled on an open-drain-style output, it does not
output a voltage level without an appropriate pull-up or
pull-down resistor. If 1 V is forced on the drain, the
current sinking/sourcing will exceed the ability of the
transistor, and the device could be damaged.
The AG pad is turned on via the corresponding GDONx
pin in the Analog Block macro, where x is the number of
the corresponding Analog Quad for the AG pad to be
enabled (GDON0 to GDON9).
The rate at which the gate voltage of the external
MOSFET slews is determined by the current, I
or sunk by the AG pin and the gate-to-source
capacitance, C
approximation, the slew rate is given by
dv/dt = I
Gate Driver
From FPGA
MOSFET
(GDONx)
Power
g
AG
/ C
Driver
Gate
GS
GS
, of the external MOSFET. As an
AT
Temperature
Digital
Input
Monitor
Prescaler
Monitor Block
Load Side
Temperature
(DATOUTx)
To FPGA
EQ
To Analog MUX
2-5.
g
, sourced
EQ 2-5