SLUS530D − SEPTEMBER 2002 − REVISED SEPTEMBER 2003
www.ti.com
12
FUNCTIONAL DESCRIPTION
BATTERY PRE-CONDITIONING
During a charge cycle if the battery voltage is below the V
(LOWV)
threshold, the bqTINY applies a precharge current,
I
O(PRECHG)
, to the battery. This feature revives deeply discharged cells. The resistor connected between the ISET
and V
SS
, R
SET
, determines the precharge rate. The V
(PRECHG)
and K
(SET)
parameters are specified in the
specifications table.
I
O (PRECHG)
+
V
(PRECHG)
K
(SET)
R
SET
The bqTINY activates a safety timer, t
(PRECHG)
, during the conditioning phase. If V
(LOWV)
threshold is not reached
within the timer period, the bqTINY turns off the charger and enunciates FAULT on the STAT1 and STAT2 pins. Refer
to Timer Fault Recovery section for additional details.
BATTERY CHARGE CURRENT
The bqTINY offers on-chip current regulation with programmable set point. The resistor connected between the ISET
and V
SS
, R
SET
, determines the charge rate. The V
(SET)
and K
(SET)
parameters are specified in the specifications
table.
I
O (OUT)
+
V
(SET)
K
(SET)
R
SET
BATTERY VOLTAGE REGULATION
Voltage regulation feedback is accomplished through the BAT pin. This input is tied directly and close to the positive
side of the battery pack. The bqTINY monitors the battery-pack voltage between the BAT and VSS pins. When the
battery voltage rises to V
O(REG)
threshold, the voltage regulation phase begins and the charging current begins to
taper down.
As a safety backup, the bqTINY also monitors the charge time in the charge mode. If termination does not occur within
this time period, t
(CHG)
, the bqTINY turns off the charger and enunciates FAULT on the STAT1 and STAT1 pins. Refer
to the Timer Fault Recovery section for additional details.
CHARGE TAPER DETECTION, TERMINATION AND RECHARGE
The bqTINY monitors the charging current during the voltage regulation phase. Once the taper threshold, I
(TAPER)
,
is detected the bqTINY initiates the taper timer, t
(TAPER)
. Charge is terminated after the timer expires. The resistor
connected between the ISET and V
SS
, R
SET
, determines the taper detection level. The V
(TAPER)
and K
(SET)
parameters are specified in the specifications table.
I
(TAPER)
+
V
(TAPER)
K
(SET)
R
SET
The bqTINY resets the taper timer in the event that the charge current returns above the taper threshold, I
(TAPER)
.
In addition to the taper current detection, the bqTINY terminates charge in the event that the charge current falls below
the I
(TERM)
threshold. This feature allows for quick recognition of a battery removal condition or insertion of a fully
charged battery. Note that taper timer is not used for I
(TERM)
detection. The resistor connected between the ISET
and V
SS
, R
SET
, determines the taper detection level. The V
(TERM)
and K
(SET)
parameters are specified in the
specifications table.
I
(TERM)
+
V
(TERM)
K
(SET)
R
SET
(3)
(4)
(5)
(6)
Summary of Contents for PV420S
Page 1: ...SERVICE MANUAL PV420S WWW BBK RU ...
Page 72: ... 69 CXD3068Q Block Diagram ...
Page 73: ... 70 CXD3068Q Pin Configuration ...
Page 122: ... 119 CXD3068Q Timing Chart 1 3 ...
Page 123: ... 120 CXD3068Q Timing Chart 1 4 ...
Page 124: ... 121 CXD3068Q Timing Chart 1 5 ...
Page 129: ... 126 CXD3068Q Timing Chart 2 1 ...
Page 130: ... 127 CXD3068Q Block Diagram 2 2 ...
Page 131: ... 128 CXD3068Q Timing Chart 2 3 ...
Page 134: ... 131 CXD3068Q Timing Chart 2 6 ...
Page 138: ... 135 CXD3068Q VCO C Mode Fig 3 3 Access Flow Chart Using VCO Control ...
Page 140: ... 137 CXD3068Q Block Diagram 4 1 ...
Page 143: ... 140 CXD3068Q Timing Chart 4 4 ...
Page 147: ... 144 CXD3068Q Fig 4 6 a Auto Focus Flow Chart Fig 4 6 b Auto Focus Timing Chart ...
Page 148: ... 145 CXD3068Q Fig 4 7 a 1 Track Jump Flow Chart Fig 4 7 b 1 Track Jump Timing Chart ...
Page 149: ... 146 CXD3068Q Fig 4 8 a 10 Track Jump Flow Chart Fig 4 8 b 10 Track Jump Timing Chart ...
Page 150: ... 147 CXD3068Q Fig 4 9 a 2N Track Jump Flow Chart Fig 4 9 b 2N Track Jump Timing Chart ...
Page 151: ... 148 CXD3068Q Fig 4 10 a Fine Search Flow Chart Fig 4 10 b Fine Search Timing Chart ...
Page 152: ... 149 CXD3068Q Fig 4 11 a M Track Move Flow Chart Fig 4 11 b M Track Move Timing Chart ...
Page 157: ... 154 CXD3068Q Fig 4 15 CD TEXT Data Timing Chart ...
Page 162: ... 159 CXD3068Q Fig 5 3a Fig 5 3b ...
Page 196: ... 193 CXD3068Q Description of Data Readout ...
Page 200: ... 197 CXD3068Q ...
Page 201: ... 198 CXD3068Q ...
Page 202: ... 199 CXD3068Q ...
Page 207: ... 204 CXD3068Q Package Outline Unit mm ...
Page 208: ...This data sheet has been made from recycled paper to help protect the environment 205 ...
