Datasheet

TPS65930/TPS65920
SWCS037G–MAY 2008– REVISED APRIL 2011 www.ti.com
Table 4-13. Backup Battery Charger Characteristics (continued)
Parameter Test Conditions Min Typ Max Unit
Backup battery charging current VBACKUP = 2.8 V, BBCHEN = 1, BBISEL = 00 10 25 45 μA
VBACKUP = 2.8 V, BBCHEN = 1, BBISEL = 01 105 150 270 μA
VBACKUP = 2.8 V, BBCHEN = 1, BBISEL = 10 350 500 900 μA
VBACKUP = 2.8 V, BBCHEN = 1, BBISEL = 11 0.7 1 1.8 mA
VBACKUP = 0 V, BBCHEN = 1, BBISEL = 00 17.5 25 45 μA
VBACKUP = 0 V, BBCHEN = 1, BBISEL = 01 105 150 270 μA
VBACKUP = 0 V, BBCHEN = 1, BBISEL = 10 350 500 900 μA
VBACKUP = 0 V, BBCHEN = 1, BBISEL = 11 0.7 1 1.8 mA
End backup battery charging voltage: I
VBACKUP
= –10 μA, BBSEL = 00 2.4 2.5 2.6 V
VBBCHGEND
I
VBACKUP
= –10 μA, BBSEL = 01 2.9 3.0 3.1 V
I
VBACKUP
= –10 μA, BBSEL = 10 3.0 3.1 3.2 V
I
VBACKUP
= –10 μA, BBSEL = 11 3.1 3.2 3.3 V
4.3.2 Battery Monitoring and Threshold Detection
4.3.2.1 Power On/Power Off and Backup Conditions
Table 4-14 lists the threshold levels of the battery.
Table 4-14. Battery Threshold Levels
Parameter Test Conditions Min Typ Max Unit
Main battery charged threshold Measured on VBAT terminal 3.1 3.2 3.3 V
VMBCH
Main battery low threshold VMBLO VBACKUP = 3.2 V, measured on VBAT terminal (monitored 2.55 2.7 2.85 V
on terminal ONNOFF)
Main battery high threshold VMBHI Measured on terminal VBAT, VBACKUP = 0 V 2.5 2.65 2.95 V
Measured on terminal VBAT, VBACKUP = 3.2 V 2.5 2.85 2.95
Batteries not present threshold VBNPR Measured on terminal VBACKUP with VBAT < 2.1 V 1.6 1.8 2.0 V
Measured on terminal VBAT with VBACKUP = 0 V 1.95 2.1 2.25
(monitored on terminal VRRTC)
4.3.3 VRRTC LDO Regulator
The VRRTC voltage regulator is a programmable, low dropout, linear voltage regulator supplying (1.5 V)
the embedded real-time clock (32.768-kHz oscillator) and dedicated I/Os of the digital host counterpart.
The VRRTC regulator is also the supply voltage of the power-management digital state-machine. The
VRRTC regulator is supplied from the UPR line, switched on by the main or backup battery, depending on
the system state. The VRRTC output is present as long as a valid energy source is present. The VRRTC
line is supplied by an LDO when VBAT > 2.7, and a clamp circuit when in backup mode. Table 4-15
describes the regulator characteristics.
Table 4-15. VRRTC LDO Regulator Characteristics
Parameter Test Conditions Min Typ Max Unit
Output Load Conditions
Filtering capacitor Connected from VRTC.OUT to analog ground 0.3 1 2.7 μF
Filtering capacitor ESR 20 600 mΩ
Electrical Characteristics
V
IN
Input voltage On mode 2.7 VBAT 4.5 V
V
OUT
Output voltage On mode 1.45 1.5 1.55 V
46 Power Module Copyright © 2008–2011, Texas Instruments Incorporated
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