MAX14900E Datasheet, PDF (14/31 Pages) Maxim Integrated Products – Global and Per-Channel Diagnostics

MAX14900E
Octal, High-Speed, Industrial, High-Side Switch
Table 1. Serial/Parallel Operating Modes
OPERATING MODE
Parallel mode with optional SPI
configuration, diagnostics, and monitoring
8-bit serial mode with SPI setting and
diagnostics
8-bit serial mode with SPI configuration
and diagnostics
16-bit serial mode with SPI setting,
configuration, diagnostics, and monitoring
16-bit serial mode with SPI configuration,
diagnostics, and monitoring
X = Don’t care
SRIAL S16/IN8
0
X
1
0
1
0
1
1
1
1
CNFG/
IN7
X
0
1
0
1
SDI DATA
SETTING CONFIG
N/A
16-bit
8-bit
N/A
N/A
8-bit
8-bit
8-bit
N/A
16-bit
SDO DATA
FAULT STATUS
8-bit
8-bit
8-bit
N/A
8-bit
N/A
8-bit
8-bit
8-bit
8-bit
Detailed Description
The MAX14900E is an octal low-propagation delay
850mA high-side switch that can be operated as a push-
pull driver with high switching-rate capability. Each chan-
nel can be configured to operate in high-side or push-pull
mode. Push-pull mode drives capacitive loads such as
long cables that need to be driven at high switching rates.
In high-side mode, each channel switches up to 850mA
load current with 165mΩ (max) on-resistance.
The MAX14900E’s switches/drivers are configured
either individually by a serial SPI interface and/or glob-
ally by a parallel interface. In parallel operating mode
(SRIAL = low), the IN_ inputs directly control the O_ outputs
and the SPI interface configures each channel and reads
back diagnostic and state status. In serial operating mode
(SRIAL = high), the SPI interface is used to configure and
set the state of each channel while the parallel inputs
provide optional configuration possibilities.
Current limiting, overload protection, and thermal
shutdown circuitry protect each switch/driver. The device
features per-channel diagnostic detection that feeds
back per-channel thermal shutdown and output state
information. In high-side mode, multiple channels can be
connected in parallel to achieve higher load currents.
Serial/Parallel Operating Modes
A serial SPI and parallel interface allow configuration,
monitoring, and driving of the MAX14900E. The serial
interface supports per-channel configuration, setting, and
diagnostics/monitoring while the parallel interface allows
direct driving of the switches/outputs. Table 1 details how
Table 2. Parallel Driving Truth Table
IN_
O_ STATE
PUSH-PULL
HIGH-SIDE
0
Low
Off
1
High
On
the device utilizes each interface depending on the status
of the configuration select inputs.
Parallel Operating Mode
In parallel operating mode (SRIAL = low), the eight IN_
inputs directly set the O_ switches on/off in high-side
mode or high/low in push-pull mode (Table 2). The
serial interface can optionally be used to configure each
output as a high-side switch or as a push-pull driver and to
enable open-load detection for each high-side switch. The
serial interface can also be used in parallel mode to read
out per-channel fault, open-load detection, and output
logic state information.
The outputs can be configured globally for push-pull oper-
ation by the PUSHPL input. Global diagnostic fault and
open-load information is reported by the FAULT output.
Serial Operating Mode
In serial operating mode (SRIAL = high), the switches/
drivers are set, configured, and monitored by the SPI
interface. The S16/IN8, CNFG/IN7, CRC/IN3, and OL/IN1
inputs and the CERR/IN4 output provide further configu-
ration and monitoring options in serial operating mode.
The remaining IN_ inputs are not used. See the Serial
Controller Interface section for more information.
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