RX64M_16 Datasheet, PDF (212/228 Pages) Renesas Technology Corp – 120-MHz 32-bit RX MCU, on-chip FPU, 240 DMIPS, up to 4-MB flash memory

RX64M Group
5.10 Battery Backup Function Characteristics
5. Electrical Characteristics
Table 5.52 Battery Backup Function Characteristics
Conditions: VCC = AVCC0 = AVCC1 = VCC_USB = 2.7 to 3.6 V, 2.7 ≤ VREFH0 ≤ AVCC0,
VCC_USBA = AVCC_USBA = 3.0 to 3.6 V,
VSS = AVSS0 = AVSS1 = VREFL0 = VSS_USB = VSS1_USBA = VSS2_USBA = PVSS_USBA = AVSS_USBA = 0 V,
V_BATT = 2.0 to 3.6 V, T_a = T_opr
Item
Symbol
Min.
Typ.
Max.
Unit
Test
Conditions
Voltage level for switching to battery backup
Lower-limit V_BATT voltage for power supply switching due to
VCC voltage drop
VCC-off period for starting power supply switching
V_DETBATT
V_BATTSW
t_VOFFBATT
2.50
2.70
200
2.60
—
—
2.70
—
—
V Figure 5.84
μs
Note: The VCC-off period for starting power supply switching indicates the period in which VCC is below the minimum value of the
voltage level for switching to battery backup (V_DETBATT).
VCC
V_DETBATT
t_VOFFBATT
VCC voltage
guaranteed range
VBATT
V_BATTSW
VBATT
Switching prohibited
Backup power
area
VCC supply
VBATT supply
VBATT
Switching prohibited
VCC supply
VBATT voltage
guaranteed range
Note. _{The VBATT voltage when the supplied power source switches from Vcc to VBATT should not be lower than VBATTSW,}
the lower-limit VBATT voltage for switching between power supplies due to a drop in the VCC voltage.
Figure 5.84 Battery Backup Function Characteristics
R01DS0173EJ0110 Rev.1.10
Oct 24, 2016
Page 212 of 228