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AT24C21_03 Datasheet, PDF (3/17 Pages) ATMEL Corporation – 2-wire Serial EEPROM
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AT24C21
Pin Description
SERIAL CLOCK (SCL): The SCL input is used to positive edge clock data into each
EEPROM device and negative edge clock data out of each device.
SERIAL DATA (SDA): The SDA pin is bidirectional for serial data transfer. This pin is
open-drain driven and may be wire-ORed with any number of other open drain or open
collector devices.
SERIAL CLOCK (VCLK): Upon power-up, the device is in the Transmit-only mode and
will transmit the entire memory contents via the SDA pin with positive signals on the
VCLK pin.
Memory Organization AT24C21, 1K SERIAL EEPROM: Internally organized with 128 pages of one byte each.
The 1K requires a 7-bit data word address for random word addressing.
DC Characteristics
Applicable over recommended operating range from: TAI = -40°C to +85°C, TAC = 0°C to +70°C, VCC = +2.5V to +5.5V
(unless otherwise noted).
Symbol Parameter
Test Condition
Min
Typ
Max
Units
VCC
Supply Voltage
2.5
5.5
V
ICC
Supply Current VCC = 5.0V
READ at 100 KHz
0.4
1.0
mA
ICC
Supply Current VCC = 5.0V
WRITE at 100 KHz
2.0
3.0
mA
ISB
Standby Current
VCC = 2.5V
VIN = VCC or VSS
VCC = 5.0V
VIN = VCC or VSS
3.0
4.0
µA
12.0
30.0
µA
ILI
Input Leakage Current
VIN = VCC or VSS
0.10
1.0
µA
ILO
Output Leakage Current
VOUT = VCC or VSS
VIL
Input Low Level(1) SCL, SDA Pin
Input Low Level VCLK Pin
VCC ≥ 2.7V
VCC < 2.7V
VIH
Input High Level(1) SCL, SDA Pin
Input High Level VCLK Pin
0.05
1.0
µA
-0.6
VCC × 0.7
2.0
VCC × 0.3
V
0.8
V
0.2 × VCC
V
VCC + 0.5
V
V
VOL
Note:
Output Low Level VCC = 3.0V
IOL = 2.1 mA
1. VIL min and VIH max are for reference only and not tested.
0.40
V
Pin Capacitance(1)
Applicable over recommended operating range from TA = 25°C, f = 1.0 MHz, VCC = +1.8V.
Symbol Test Condition
Max
CI/O
Input/Output Capacitance (SDA)
8
CIN
Input Capacitance (A0, A1, A2, SCL, VCLK)
6
Note: 1. This parameter is characterized and is not 100% tested.
Units
pF
pF
Conditions
VI/O = 0V
VIN = 0V
3
0405I–SEEPR–7/03
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