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Texas Instruments LM8333GGR8AXS/NOPB
- Part No.:
- LM8333GGR8AXS/NOPB
- Manufacturer:
- Texas Instruments
- Category:
- Controllers
- Package:
- 49-TFBGA, CSPBGA
- Datasheet:
-
LM8333GGR8AXS/NOPB.pdf
- Description:
- IC MOBILE I/O COMPANION 49-MIC
- Quantity:
- Payment:
- Shipping:
Inventory:2,656
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Product details
Overview
LM8333GGR8AXS/NOPB from Texas Instruments is a mobile I/O companion IC that offloads keypad scanning and I/O expansion from the host processor in portable devices. It supports 8×8 standard key matrix plus 8 special-function keys (72 total), features a 15-byte FIFO buffer, ACCESS.bus (I²C-compatible) interface at up to 400 kHz, and delivers <2 µA standby current. It is used in mobile phones and smart handheld devices for low-power, reliable key-event encoding.
For engineers reviewing the LM8333GGR8AXS/NOPB datasheet, LM8333GGR8AXS/NOPB pinout, LM8333GGR8AXS/NOPB application, or LM8333GGR8AXS/NOPB equivalent, key selection considerations include its 32-pin WQFN package, programmable debounce (1–255 × 3 ms), active-time control (1–255 × 3 ms), dual external interrupt-capable GPIOs (GEN_IO_0/GEN_IO_1), and mandatory watchdog timer requiring WD_OUT-to-RESET connection.
Technical Context
The LM8333GGR8AXS/NOPB implements a fully static architecture with hardware-controlled Halt mode entry after configurable inactivity (default 500 ms), reducing supply current to <2 µA. Its internal RC oscillator (nominally 1 MHz, ±30% variation) drives keypad scanning at ~4 ms intervals and supports wake-up via WAKE_INx pins or ACCESS.bus activity.
It uses an I²C-compatible ACCESS.bus slave interface (fixed 7-bit address 0xA2) with support for repeated-start and stop-start sequences. All host communication is command-driven (e.g., FIFO_READ 0x20, READ_INT 0xD0), and interrupt handling relies on IRQ assertion with status/error code registers accessible only via dedicated commands.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Operating Voltage | 2.25 V to 2.9 V - defines minimum battery voltage for reliable operation in single-cell Li-ion or Li-poly systems |
| Standby Current | <2 µA - enables multi-week battery life in always-on keypad monitoring without host intervention |
| I²C Speed | Up to 400 kHz - supports fast host polling and command execution without bus contention in shared peripheral systems |
| FIFO Depth | 15 bytes - stores up to 14 key events plus termination byte, preventing data loss during burst press/release sequences |
| Debounce Range | 1–255 × 3 ms (3 ms to ~765 ms) - allows tuning for mechanical switch noise or capacitive touch panel integration |
| Active Time Range | 1–255 × 3 ms (3 ms to ~765 ms) - configures post-release scanning window before entering ultra-low-power Halt mode |
| Keypad Capacity | 8×8 matrix + 8 SF keys = 72 keys - supports full QWERTY or numeric keypads with dedicated wake-up function keys |
Pinout & Package
LM8333GGR8AXS/NOPB is packaged in a 32-pin WQFN (Package Number NJE0032A), 5 mm × 5 mm, 0.5 mm pitch, wettable flank, RoHS-compliant and lead-free.
| Pin | Circuit Role | Design Meaning |
|---|---|---|
| WAKE_IN0–WAKE_IN7 | Keyboard scan input / wake-up trigger | Eight dedicated inputs for SF key grounding; each forces wake-up and overrides other keys in same row |
| K_OUT0–K_OUT7 | Keyboard scan output | Eight open-drain outputs driving column lines of keypad matrix; sink current up to 16 mA per pin |
| GEN_IO_0, GEN_IO_1 | Programmable GPIO with interrupt | Configurable as input/output; rising/falling edge triggers IRQ and wakes device from Halt mode |
| GEN_IO_2, GEN_IO_3 | General-purpose I/O | Software-configurable direction/output state; GEN_IO_3 lacks true Hi-Z mode and defaults to weak pullup when input |
| SDA, SCL | I²C-compatible bidirectional bus | ACCESS.bus interface compliant with I²C standard; supports 400 kHz operation and repeated-start protocol |
| IRQ | Open-drain interrupt output | Asserted low on key event, error, or enabled GPIO transition; cleared only by READ_INT (0xD0) command |
| PWM | Programmable pulse-width modulated output | 16-bit timer-driven output; configurable high/low times (1–65535 × 1 µs); also usable as general-purpose push-pull output |
| WD_OUT | Watchdog timer output | Mandatory connection to host RESET line; asserts low if watchdog is not serviced within timeout period |
| RESET | Asynchronous reset input | Active-low signal that resets internal state, FIFO, and registers; required for power-on initialization |
| CLK_IN | RC oscillator timing input | Connect to GND via 68 kΩ resistor to set nominal 1 MHz internal clock; determines scan interval and timer resolution |
Key Features
| Feature | Design Value |
|---|---|
| Hardware Halt Mode Entry | Automatic transition to sub-2 µA standby after configurable inactivity - eliminates need for host firmware sleep management |
| Dual External Interrupt GPIOs | GEN_IO_0 and GEN_IO_1 support edge-triggered wake-up and IRQ assertion - enables system-level low-power coordination without polling |
| 72-Key Scan Capability | 8×8 matrix + 8 SF keys with row override logic - supports complex keypads while preserving wake-up priority for critical functions |
| 15-Byte Event FIFO | Stores encoded key-press/release events with MSB flag (1=press, 0=release) - ensures deterministic host read sequence without race conditions |
| Mandatory Watchdog Timer | WD_OUT must be connected to host RESET - prevents system lockup due to I²C bus hang or host firmware failure |
Applications
| Mobile Phone Keypad Interface | PDA System Control Panel |
|---|---|
Use Scenario: Mechanical keypad with 40+ keys in slim smartphone form factor requiring low quiescent current and reliable wake-up. IC Role / Device Role / Timing Role: Offloads real-time scanning, debouncing, and event encoding; generates IRQ on key press/release; manages Halt/Active transitions autonomously. Use Value: Reduces host CPU load by >95% during idle; extends battery life via <2 µA standby; eliminates missed key events using 15-byte FIFO and error reporting (KEYOVR, FIFOOVR). | Use Scenario: PDA with hybrid input: physical navigation keys + soft-function buttons requiring context-aware wake-up and I/O expansion. IC Role / Device Role / Timing Role: Provides 8 SF keys mapped to WAKE_INx for instant system wake; supplies four programmable GPIOs for status LEDs or sensor enable signals. Use Value: Enables zero-latency wake from deep sleep using SF keys; allows host to repurpose GEN_IO_2/GEN_IO_3 as LED drivers or sensor controls without additional ICs. |
| Smart Handheld Media Player UI | Personal Media Player Power Management |
Use Scenario: Portable media player with tactile playback controls (play/pause/next/prev) and volume rocker, operating on coin-cell or small Li-ion. IC Role / Device Role / Timing Role: Scans dedicated control keys; uses PWM output to drive backlight dimming; monitors GEN_IO_0 for headphone detect interrupt. Use Value: Integrates UI control, backlight PWM, and accessory detection in one 5×5 mm package; achieves 12-month shelf life via <2 µA Halt current. | Use Scenario: Battery-powered media player requiring fail-safe reset behavior and robust I²C communication under voltage droop. IC Role / Device Role / Timing Role: Implements mandatory watchdog timer (WD_OUT → RESET); handles I²C bus recovery after Halt wake-up NACK; reports errors (CMDOVR, CMDUNK) via READ_ERROR. Use Value: Prevents unresponsive UI lockups; ensures host recovers from bus stalls using documented retry protocol; provides diagnostic visibility into command execution failures. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar I/O companion applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TCA6408A | 8-bit I/O expander only; no keypad scanning, FIFO, or watchdog; I²C up to 400 kHz; no WAKE_INx/SF key support | Limited to basic GPIO expansion; cannot replace LM8333GGR8AXS/NOPB in keypad-centric designs | Select when only digital I/O extension is needed and key-scan functionality is handled elsewhere |
| PCA9555 | 16-bit I/O expander with interrupt output; no built-in keypad engine, FIFO, or PWM; supports 1 MHz I²C; no watchdog or Halt mode | Suitable for general-purpose I/O but lacks integrated key-scan logic, debounce, or low-power autonomous operation | Choose for higher pin count and faster I²C where autonomous keypad management is unnecessary |
Compared with TCA6408A and PCA9555, LM8333GGR8AXS/NOPB uniquely integrates keypad scanning, 15-byte FIFO, programmable debounce/active timing, dual wake-up GPIOs, and mandatory watchdog - making it irreplaceable in space-constrained, battery-sensitive handhelds requiring full key-event autonomy.
Availability
LM8333GGR8AXS/NOPB is available at Aetrix Electronics and suitable for mobile phones, personal digital assistants, smart handheld devices, and personal media players requiring stable component supply across long-lifecycle consumer electronics programs.
Supply support for LM8333GGR8AXS/NOPB includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.
Manufacturer
Texas Instruments is a global semiconductor company headquartered in Dallas, Texas, delivering analog and embedded processing solutions for industrial, automotive, and personal electronics markets.
The LM8333GGR8AXS/NOPB belongs to TI's Mobile I/O Companion product line, designed specifically to reduce host processor overhead and power consumption in battery-powered handheld devices with physical keypads and auxiliary control interfaces.
FAQ
What is the required connection for WD_OUT on LM8333GGR8AXS/NOPB?
The WD_OUT pin on LM8333GGR8AXS/NOPB must be connected directly to the host microcontroller's RESET input. This is mandatory because the internal watchdog timer is always enabled in hardware. Failure to connect WD_OUT to RESET disables the safety mechanism, risking system lockup during I²C bus hangs or host firmware faults. The LM8333GGR8AXS/NOPB datasheet explicitly states this requirement in the WATCHDOG TIMER section.
Does LM8333GGR8AXS/NOPB support true I²C or only ACCESS.bus?
LM8333GGR8AXS/NOPB implements a fully I²C-compatible ACCESS.bus interface, supporting standard I²C protocols including 7-bit addressing (slave address 0xA2), repeated-start conditions, and 400 kHz operation. It responds to standard I²C START/STOP sequences and acknowledges correctly after wake-up retries. While branded as ACCESS.bus, its electrical and protocol behavior aligns with the I²C specification - confirmed by TI's SNLS246K datasheet stating "fully compliant with the I2Cbus standard".
How does LM8333GGR8AXS/NOPB handle simultaneous key presses?
LM8333GGR8AXS/NOPB detects and reports simultaneous key presses beyond two as an error condition (KEYOVR), asserting the IRQ output and setting the ERROR bit in the interrupt code. When KEYOVR occurs, the device loads no new events into the FIFO until cleared. Host software must read the error code via READ_ERROR (0xF0) and decide whether to discard or interpret ambiguous scan patterns. This behavior is defined in the KEYPAD SCANNING section of the LM8333GGR8AXS/NOPB datasheet.
Can GEN_IO_3 on LM8333GGR8AXS/NOPB be configured in high-impedance input mode?
No, GEN_IO_3 on LM8333GGR8AXS/NOPB cannot be placed in true high-impedance (Hi-Z) input mode. According to the General-Purpose I/O Pin Configuration table in the LM8333GGR8AXS/NOPB datasheet, when GEN_IO_3 is programmed as an input, it defaults to weak pullup only - there is no configuration bit to disable the pullup and achieve Hi-Z. This differs from GEN_IO_0–GEN_IO_2, which support Hi-Z via GEN_IO_DIR=0 and GEN_IO_OUT=0.
What is the default debounce time for LM8333GGR8AXS/NOPB, and how is it adjusted?
The default debounce time for LM8333GGR8AXS/NOPB is 10 ms, implemented as 10 × 3 ms = 30 ms per the DEBOUNCE command (0x22) specification. It is adjusted by writing an 8-bit value (1–255) to the DEBOUNCE register, where actual time equals n × 3 ms. For example, writing 0x64 (100 decimal) sets debounce to 300 ms. This parameter is independent of the active time setting and must be less than the ACTIVE time value to avoid functional conflict.
LM8333GGR8AXS/NOPB Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Package/Case:
- 49-TFBGA, CSPBGA
- Programmable:
- Not Verified
- Protocol:
- -
- Function:
- Controller
- Interface:
- ACCESS.bus, I2C
- Standards:
- -
- Voltage - Supply:
- 2.25V ~ 2.9V
- Current - Supply:
- 6mA
- Operating Temperature:
- -40°C ~ 85°C
- Supplier Device Package:
- 49-CSBGA (4x4)
- Grade:
- -
- Qualification:
- -
LM8333GGR8AXS/NOPB FAQ
1.How can I place an order for LM8333GGR8AXS/NOPB through Aetrix?
Please submit a Request for Quotation (RFQ) for LM8333GGR8AXS/NOPB on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for LM8333GGR8AXS/NOPB reliable?
The price and inventory of LM8333GGR8AXS/NOPB are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM8333GGR8AXS/NOPB is usually 5 days.
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We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM8333GGR8AXS/NOPB transactions.
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LM8333GGR8AXS/NOPB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM8333GGR8AXS/NOPB order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for LM8333GGR8AXS/NOPB?
For technical support, including LM8333GGR8AXS/NOPB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM8333GGR8AXS/NOPB requirements.
6.How does Aetrix verify that LM8333GGR8AXS/NOPB is sourced from the original manufacturer or authorized distributors?
All LM8333GGR8AXS/NOPB products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that LM8333GGR8AXS/NOPB meets industry standards.
7.What is the process for return or replacement of LM8333GGR8AXS/NOPB?
All LM8333GGR8AXS/NOPB units undergo pre-shipment inspection (PSI). If there is an issue with LM8333GGR8AXS/NOPB, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The LM8333GGR8AXS/NOPB part is unused and in its original packaging.
Return procedure for LM8333GGR8AXS/NOPB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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