The MAX6966/MAX6967 serial-interfaced peripherals
provide microprocessors with 10 I/O ports rated to 7V.
Each port can be individually configured as either:
- A 20mA constant-current LED driver (static or pulsewidth
modulated (PWM)).
- A 10mA constant-current LED driver (static or PWM).
- An open-drain logic output.
- An overvoltage-protected Schmitt logic input.
Analog and switching LED intensity control is built in:
- Individual 8-bit PWM control per output.
- Individual 1-bit analog control (half/full) per output.
- Global 3-bit analog control applies to all LED outputs.
PWM timing of the 10 port outputs may be optionally
staggered, consecutively phased in 45° increments.
This spreads the PWM load currents over time in eight
steps, helping to even out the power-supply current
and reduce the RMS current.
The MAX6966/MAX6967 can be configured to awake
from shutdown on receipt of a minimum 3ms pulse on
the active-low CS input. This hardware-wakeup feature allows a
power-management controller or similar ASIC to enable
the MAX6966/MAX6967 with preconfigured LED intensity
settings.
Shutdown can be programmed to wait up to 4s, fade
down the sink currents to zero for a period of 1/16s to
4s, and then shut down. A similar ramp-up from shutdown
can be programmed for 1/16s to 4s.
The MAX6966/MAX6967 support hot insertion. All port
pins remain high impedance in power-down (V+ = 0V)
with up to 8V asserted on them.
The DOUT/OSC pin can be configured as either the
serial interface data output or optional PWM clock
input. The MAX6966 powers up defaulting as DOUT
output. The MAX6967 defaults as OSC input.
For a similar part without the constant-current controls,
refer to the MAX7317 data sheet.
Applications
- Cell Phones
- Keypad Backlights
- LCD Backlights
- LED Status Indication
- Portable Equipment
- RGB LED Drivers
