RX230 Datasheet, PDF (158/177 Pages) Renesas Technology Corp – 54-MHz 32-bit RX MCUs, built-in FPU, 88.56 DMIPS, up to 512-KB flash memory

RX230 Group, RX231 Group
5. Electrical Characteristics
5.12 Battery Backup Function Characteristics
Table 5.60 Battery Backup Function Characteristics
Conditions: 1.8 V ≤ VCC = VCC_USB = AVCC0 ≤ 5.5 V, 1.8 V ≤ VBATT ≤ 5.5 V, VSS = AVSS0 = VREFL0 = VSS_USB = 0 V,
T_a = –40 to +105°C
Item
Symbol
Min.
Typ.
Max.
Unit Test Conditions
Voltage level for switching to battery backup (falling)
Hysteresis width
VCC-off period for starting power supply switching
Allowable voltage change rising/falling gradient
V_DETBATT
V_VBATTH
t_VOFFBATT
dt/dVCC
1.99
—
—
1.0
2.09
100
—
—
2.19
V Figure 5.78
—
mV
350
μs
—
ms/V Figure 5.7
Level for detection of voltage VBTLVDLVL[1:0] = 10b V_DETBATLVD 2.11
drop on the VBATT pin (falling) _{VBTLVDLVL[1:0] = 11b}
1.87
2.20
2.00
2.29
2.13
V Figure 5.78
V
Hysteresis width for detection of voltage drop on the
VBATT pin
V_BATLVDH
—
50
—
mV
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).
V_DETBATT
VCC
t_VOFFBATT
VCC
Cannot
Be
raised
V_VBATTH
VCC voltage
guaranteed
range
VBATT
V_DETBATLVD
Backup power
supply area
VCC supplied
V_BATLVDH
VBATT supplied
Figure 5.78 Battery Backup Function Characteristics
VBATT voltage
guaranteed
range
VCC supplied
R01DS0261EJ0110 Rev.1.10
Oct 30, 2015
Page 158 of 177