BR24G512-3A Datasheet, PDF (22/33 Pages) Rohm – Serial EEPROM Series Standard EEPROM I2C BUS EEPROM (2-Wire)

BR24G512-3A
I/O Equivalence Circuit
Input (A0, A1, A2, SCL, WP)
Input / output (SDA)
Datasheet
Figure 50. Input Pin Circuit Diagram
Figure 51. Input / Output Pin Circuit Diagram
Power-Up / Down Conditions
At power on, the IC’s internal circuits may go through unstable low voltage area as the Vcc rises, making the IC’s internal
logic circuit not completely reset, hence, malfunction may occur. To prevent this, the IC is equipped with POR circuit and
LVCC circuit. To assure the operation, observe the following conditions at power ON.
1. Set SDA = 'H' and SCL ='L' or 'H’
2. Start power source so as to satisfy the recommended conditions of t_R, t_OFF, and V_bot for operating POR circuit.
tR
VCC
Recommended conditions of t_R, t_OFF,V_bot
t_R
t_OFF
V_bot
tOFF
Vb ot
0
10ms or below 10ms or larger 0.3V or below
100ms or below 10ms or larger 0.2V or below
Figure 52. Rise Waveform Diagram
3. Set SDA and SCL so as not to become 'Hi-Z'.
When the above conditions 1 and 2 cannot be observed, take the following countermeasures.
(1) In the case when the above condition 1 cannot be observed such that SDA becomes 'L' at power ON.
→Control SCL and SDA as shown below, to make SCL and SDA, 'H' and 'H'.
VCC
SCL
tLOW
SDA
After Vcc becomes stable
tDH tSU:DAT
Figure 53. When SCL= 'H' and SDA= 'L'
After Vcc becomes stable
tSU: DAT
Figure 54. When SCL='L' and SDA='L'
(2) In the case when the above condition 2 cannot be observed.
→After power source becomes stable, execute software reset(Page18).
(3) In the case when the above conditions 1 and 2 cannot be observed.
→Carry out (1), and then carry out (2).
Low Voltage Malfunction Prevention Function
LVCC circuit prevents data rewrite operation at low power, and prevents write error. At LVCC voltage (Typ =1.2V) or below,
data rewrite is prevented.
Noise Countermeasures
1. Bypass Capacitor
When noise or surge gets in the power source line, malfunction may occur, therefore, it is recommended to attach a bypass
capacitor (0.1μF) between the IC’s V_CC and GND pins. Attach it as close to the IC as possible. In addition, it is also
recommended to attach a bypass capacitor between board’s V_CC and GND.
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TSZ02201-0R2R0G100360-1-2
25.Feb.2013 Rev.002