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Features
8 × 8 standard keys
8 special function keys (SF keys) providing a total of 72 keys for the maximum keyboard matrix
ACCESS.bus (I
2C-compatible) communication interface to the host
Four general purpose host programmable I/O pins with two optional (slow) external Interrupts
15-byte FIFO buffer to store key pressed and key released events
Error control with error reports on (FIFO overrun, Keypad overrun, invalid command)
Host programmable PWM
Host programmable active time and debounce time
Description The LM8333 Mobile I/O Companion offloads the burden of keyboard scanning from the host, while providing extremely low power
consumption in both operational and standby modes. It supports keypad matrices up to 8 × 8 in size (plus another 8 special-function
keys), for portable applications such as cellphones, PDAs, games, and other handheld applications.
Key press and release events are encoded into a byte format and loaded into a FIFO buffer for retrieval by the host processor.
An interrupt output (IRQ) is used to signal events such as keypad activity, a state change on either of two interrupt-capable
general-purpose I/O pins, or an error condition. Interrupt and error codes are available to the host by reading dedicated
registers.
Four general-purpose I/O pins are available, two of which have interrupt capability. A pulse-width modulated output based
on a host-programmable internal timer is also available, which can be used as a general-purpose output if the PWM function
is not required.
To minimize power, the LM8333 automatically enters a low-power standby mode when there is no keypad, I/O, or host activity.
The device is packaged in a 32–pin Leadless Leadframe package (LLP) and a 49-pin MICRO-ARRAY . Both are chip-scale packages.
Applications
Mobile phones
Personal Digital Assistants (PDAs)
Smart handheld devices
Personal media players
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Also Recommended
| LM8322▲ | 1.8 V Operation, Up To 104 Keys, Up To 16 GPIO, 3 PWM |
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LM8322
