MAX14912 Datasheet, PDF (21/30 Pages) Maxim Integrated Products – Low Power and Heat Dissipation

MAX14912/MAX14913
Octal High-Speed, High-Side
Switch/Push-Pull Driver
Parallel Interface: Setting the OUT_ Output Driver
The parallel mode (SRIAL = low) uses one input pin (IN_)
to set each output (OUT_). Table 3 shows the settings that
depend on the configured mode.
In parallel setting mode (SRIAL = low), the MAX14913
can only be configured via the global configuration inputs:
PUSHPL and FLTR, not on a per-channel basis through
SPI. This means that all high-side drivers are either in
high-side or push-pull operation. Open-load detection is
enabled and cannot be disabled in parallel setting mode.
The MAX14912 can be configured with full flexibility in
parallel setting mode.
Serial Controller Interface
The serial interface can be used in all setting modes. It
is based on CPOL = low and CPHA = low, meaning that
the SDI data is latched-in on the rising edge of CLK and
new SDO data is written on the falling edge of CLK. The
default idle CLK state needs to be low. The SDO output
is only actively driven when the SPI master drives CS low,
it is otherwise weakly pulled down by an internal 200kΩ
resistor when CS is high.
Table 3. SRIAL = Low
DRIVER MODE IN_
OUT_ STATE
High-Side
0 High-side off
High-Side
1 High-side on
Push-Pull
0 Push-pull output low
Push-Pull
1 Push-pull output high
The SPI interface provides per channel and detailed global
diagnostics. In serial setting mode (SRIAL = high), the
outputs are set on/off/high/low by the serial interface. Serial
mode also allows per channel and global configuration. In
parallel setting mode (SRIAL = low), the MAX14913 does
not allow configuration through SPI, while the MAX1912
can be configured per channel and globally.
The SPI interface can be operated in either command
mode or direct mode. Command mode is available in both
parallel and serial modes and provides higher information
content and supports more configuration options. See
Table 4 for details. Direct mode SPI is only available in
serial setting mode (SRIAL = high). In direct SPI mode,
output setting and per channel configuration is written
directly (without a command byte) and diagnostics data is
provided either in an 8 or 16-bit SPI cycle.
In both command and direct SPI modes, when the high-
side/push-pull drivers are set on/off/high/low via SPI,
the outputs change state at the end of the SPI cycle, on
the rising CS edge, with a sub 1µs propagation delay, as
defined in the Electrical Properties Table. In direct and
command mode SPI, diagnostic and status information
is sampled at the beginning of each SPI cycle, initiated
by the falling CS edge and is then sequentially written out
on SDO on each falling CLK edge. Command SPI mode
allows reading back the chip configuration and status
and diagnostics, as selected via the command byte. This
information is then written out on the following SPI cycle.
Table 4. SPI interface Modes Selection and Description
PIN
SPI
MODE
SRIAL
CMND CNFG
/IN2 /IN7
S16
/IN8
0
1
0
0
1
BITS
SDI
8
Per-channel OUT_
setting
Per-channel OUT_
16 setting and HS/PP
selection
RESULT
SDO
NOTES
Per-channel fault
Per-channel fault
and level
OUT set by SPI. FAULT is the
real-time status of the fault (driver
shutdown or open-load)
0
8
Per-channel config:
HS/PP
Per-channel fault
1
0
1
1
Per-channel config:
16 HS/PP and OL
detection on/off
Per-channel fault
and level
OUT level does not change
1
1
X
X
16
8-bit-command +
8-bit data
Previous command OUT level may or may not change
output
depending on command
0
X
X
X
16
8-bit-command +
8-bit data
Previous command
output
OUT set by INx pins. MAX14912
allows SPI configuration. MAX14913
does not allow SPI configuration.
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