24LC21A 24LC21A 24LC21A 2 1K 2.5V Dual Mode I C Serial EEPROM Features Package Types Single supply with operation down to 2.5V PDIP NC 1 8 Vcc Completely implements DDC1/DDC2 interface for monitor identification, including NC 2 7 VCLK recovery to DDC1 Pin and function compatible with 24LC21 NC 3 6 SCL Low-power CMOS technology - 1 mA typical active current VSS 4 5 SDA -10 A standby current typical at 5.5V 2 2-wire serial interface bus, I C compatible SOIC 100 kHz (2.5V) and 400 kHz (5V) compatibility 1 8 Self-timed write cycle (including auto-erase) NC Vcc Page write buffer for up to eight bytes 2 7 NC VCLK 1,000,000 erase/write cycles ensured Data retention > 200 years 3 6 NC SCL ESD Protection > 4000V 4 5 8-pin PDIP and SOIC package Vss SDA Available for extended temperature ranges - Commercial (C): 0C to +70C - Industrial (I): -40C to +85C Block Diagram Description HV Generator The Microchip Technology Inc. 24LC21A is a 128 x 8-bit dual-mode Electrically Erasable PROM. This device is I/O Memory EEPROM designed for use in applications requiring storage and Control Control Array XDEC serial transmission of configuration and control informa- Logic Logic tion. Two modes of operation have been implemented: Page Latches Transmit-only mode and Bidirectional mode. Upon SCL SDA power-up, the device will be in the Transmit-only mode, YDEC sending a serial bit stream of the memory array from 00h VCLK to 7Fh, clocked by the VCLK pin. A valid high-to-low transition on the SCL pin will cause the device to enter Sense AMP R/W Control the transition mode, and look for a valid control byte on VCC 2 the I C bus. If it detects a valid control byte from the VSS master, it will switch into Bidirectional mode, with byte selectable read/write capability of the memory array using SCL. If no control byte is received, the device will Pin Function Table revert to the Transmit-only mode after it receives 128 consecutive VCLK pulses while the SCL pin is idle. The Name Function 24LC21A is available in a standard 8-pin PDIP and VSS Ground SOIC package in both commercial and industrial SDA Serial Address/Data I/O temperature ranges. SCL Serial Clock (Bidirectional mode) VCLK Serial Clock (Transmit-only mode) VCC +2.5V to 5.5V Power Supply DDC is a trademark of the Video Electronics Standards Association. NC No Connection 2 I C is a trademark of Philips Corporation. 2003 Microchip Technology Inc. DS21160F-page 124LC21A 1.0 ELECTRICAL CHARACTERISTICS () Absolute Maximum Ratings VCC.............................................................................................................................................................................7.0V All inputs and outputs w.r.t. VSS.........................................................................................................................................-0.6V to VCC +1.0V Storage temperature ...............................................................................................................................-65C to +150C Ambient temperature with power applied................................................................................................-65C to +125C ESD protection on all pins ...................................................................................................................................................... 4 kV NOTICE: Stresses above those listed under Absolute Maximum Ratings may cause permanent damage to the device. This is a stress rating only and functional operation of the device at those or any other conditions above those indicated in the operational listings of this specification is not implied. Exposure to maximum rating conditions for extended periods may affect device reliability. TABLE 1-1: DC CHARACTERISTICS VCC = +2.5V to 5.5V DC CHARACTERISTICS Commercial (C): TA = 0C to +70C Industrial (I): TA =-40C to +85C Parameter Symbol Min Max Units Conditions SCL and SDA pins: High-level input voltage VIH 0.7 VCC V Low-level input voltage VIL 0.3 VCC V Input levels on VCLK pin: High-level input voltage VIH 2.0 V VCC 2.7V (Note) Low-level input voltage VIL 0.2 VCC V VCC < 2.7V (Note) Hysteresis of Schmitt Trigger inputs VHYS .05 VCC V (Note) Low-level output voltage VOL1 0.4 V IOL = 3 mA, VCC = 2.5V (Note) Low-level output voltage VOL2 0.6 V IOL = 6 mA, VCC = 2.5V Input leakage current ILI 1 AVIN = 0.1V to VCC Output leakage current ILO 1 AVOUT = 0.1V to VCC Pin capacitance (all inputs/outputs) CIN, COUT 10 pF VCC = 5.0V (Note) TA = 25C, FCLK = 1 MHz Operating current ICC Write 3 mA VCC = 5.5V ICC Read 1 mA VCC = 5.5V, SCL = 400 kHz Standby current ICCS 30 A VCC = 3.0V, SDA = SCL = VCC 100 A VCC = 5.5V, SDA = SCL = VCC VCLK = VSS Note: This parameter is periodically sampled and not 100% tested. DS21160F-page 2 2003 Microchip Technology Inc.