Texas Instruments bq2403 Series, User Manual

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3 Performance Specification Summary
4 Test Summary
4.1 Equipment
4.2 Equipment Setup
Performance Specification Summary
Another critical feature is power handoff. The power handoff is initiated autonomously or by request. The
PSEL (High/Low) sets which input source takes priority (AC or USB). This handoff happens immediately
on request. The CE pin (going high) immediately enables the chip; disabling it (going low) delays handoff
for 5 ms. For autonomous power selection (e.g., the selected source is lost), the IC switches sources
when the Power Good (PG) status indicates the primary selected source is no longer good. PG is defined
as >(V
BAT
+ 80 mV). This means that if the battery is dead (missing, or discharged below a useable
system voltage), the IC switches over to the other available source when the V
OUT
reaches the dead
battery voltage. This design feature prevents cycling between a stronger current-limiting source and the
USB source. In most situations, if AC power is available (prior to losing it), the battery probably would not
be discharged.
Table 1 summarizes the performance specifications of the EVM.
Table 1. Performance Specification Summary For bq24030/1/2/5 EVMs
SPECIFICATION TEST CONDITIONS MIN TYP MAX UNITS
Input DC Voltage, V
I(AC)
4.8 V 5.0 6.5
Volts
Input DC USB Voltage, V
I(USB)
5.0
Battery Charge Current, I
O(CHG)
1.0 2.0+ Amperes
Power Dissipation, bq2403x IC, 1 Cell Pdiss=(Vin-Vout)Iout +(Vin-Vbat)Ibat + see
(1)
Watts
(Vin-Vldo)I
LDO
(1)
The HPA073 (bq2403x) thermal design is optimized (8
+
vias, 0.031-inch PWB, 2 oz. copper) to give
θ
JA
~ 27°C/W.
This section covers the setup and tests performed in evaluating the EVM.
•
Power supply (+5.25 ± 0.25 VDC), current limit set to 2.0 A ± 0.2 A for AC input to the UUT
•
USB high-power port (500 mA) and cable (J1 is an alternate USB connection)
•
Three Fluke 75 DMMs (equivalent or better)
•
Oscilloscope, Model TDS220 (equivalent or better)
•
Preset the UUT power supply voltage and current prior to connection to UUT; turn off the power supply
and connect the supply to J2-AC/GND (+ to AC and – to GND).
•
Connect a 10-
Ω
load to J7-OUT/GND.
•
Connect a 1k-
Ω
load to J5-LDO/GND.
•
Connect a fully discharged (< 2.8-VDC) single-cell Li-ion or Li-polymer battery to J8-BAT+/BAT–.
•
Connect the DMMs as shown in Figure 1 .
SLUU207A – October 2004 – Revised January 2007 bq2403x (bqTiny-III™) 1.5-A Single-Chip Li-Ion 3
and Li-Pol Charge Management IC EVM
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