SLUS530D − SEPTEMBER 2002 − REVISED SEPTEMBER 2003
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14
FUNCTIONAL DESCRIPTION
BATTERY ABSENT DETECTION
For applications with removable battery packs, bqTINY provides a battery absent detection scheme to reliably detect
insertion and/or removal of battery packs.
The voltage at the BAT pin is held above the battery recharge threshold, V
(RCH)
, by the charged battery following
fast charging. When the voltage at the BAT pin falls to the recharge threshold, either by a load on the battery or due
to battery removal, the bqTINY begins a battery absent detection test. This test involves enabling a detection current,
I
(DETECT)
, for a period of t
(DETECT)
and checking to see if the battery voltage is below the pre-charge threshold,
V
(LOWV)
. Following this, the precharge current, I
O(PRECHG)
is applied for a period of t
(DETECT)
and the battery voltage
checked again to be above the recharge threshold. The purpose is to attempt to close a battery pack with an open
protector, if one is connected to the bqTINY. Passing both of the discharge and charging tests indicates a battery
absent fault at the STAT pins. Failure of either test starts a new charge cycle. For the absent battery condition the
voltage on the BAT pin rises and falls between the V
(LOWV)
and V
O(REG)
thresholds indefinitely. See Figure 7.
No
Yes
Yes
No
No
Yes
VI(BAT) <
V(RCH)
Enable
I(DETECT) for
t(DETECT)
VI(BAT) <
V(LOWV)
BATTERY
PRESENT
Begin Charge
BATTERY
PRESENT
Begin
Charge
Apply
IO(PRECHG) for
t(DETECT)
VI(BAT) >
V(RCH)
BATTERY
ABSENT
Charge Done
or
Timer Fault
Figure 7. Battery Absent Detection
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 ...