R01UH0823EJ0100 Rev.1.00
Page 1809 of 1823
Jul 31, 2019
RX23W Group
51. Electrical Characteristics
51.12 Battery Backup Function Characteristics
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
).
Figure 51.68
Battery Backup Function Characteristics
Table 51.54
Battery Backup Function Characteristics
Conditions: 1.8 V ≤ VCC = VCC_USB = AVCC0 = VCC_RF = AVCC_RF ≤ 3.6 V, 1.8 V ≤ VBATT ≤ 3.6 V,
VSS = AVSS0 = VREFL0 = VSS_USB = VSS_RF = 0 V, T
a
= –40 to +85°C
Item
Symbol
Min.
Typ.
Max.
Unit
Test Conditions
Voltage level for switching to battery backup (falling)
V
DETBATT
1.99
2.09
2.19
V
Hysteresis width
V
VBATTH
—
100
—
mV
VCC-off period for starting power supply switching
t
VOFFBATT
—
—
350
μs
Allowable voltage change rising/falling gradient
dt/dVCC
1.0
—
—
ms/V
Level for detection of voltage
drop on the VBATT pin (falling)
VBTLVDLVL[1:0] = 10b
V
DETBATLVD
2.11
2.20
2.29
V
VBTLVDLVL[1:0] = 11b
1.87
2.00
2.13
V
Hysteresis width for detection of voltage drop on the
VBATT pin
V
BATLVDH
—
50
—
mV
VCC
VBATT
Backup power
supply area
VCC supplied
VCC supplied
VBATT supplied
V
DETBATT
VCC voltage
guaranteed
range
VBATT voltage
guaranteed
range
t
VOFFBATT
VCC
Cannot
Be
raised
V
VBATTH
V
DETBATLVD
V
BATLVDH