BS EN 62637-2:2011 pdf download.Battery charging interface for small handheld multimedia devices.
The general test conditions are set out below. Manufacturers should note that the actual conditions of use could be more stringent.
Tests conducted using this conformance document do not replace EMC, ESO, safety, type approval, or any tests set by legislation in the chargers or devices using the charging interface specified in IEC 62637-1. The purpose of the conformance testing is to achieve good interoperability between different chargers and devices.
4.2 Temperature
All measurements shall be made at normal room temperature 18 CC to 25 C, unless some other temperature is specified.
4.3 Voltage
All tests are performed under nominal operating voltage as defined by the manufacturer.
5 Electrical testing of 2 mm barrel type chargers
5.1 Maximum transient voltage and current values
5.1.1 Test purpose
The purpose of this test is to verify that the charger complies with the requirements of settling time, minimum voltage and maximum voltage limits specified in IEC 62637-1, 5.2.
5.1.2 Requirements
The following requirements apply.
• Maximum charger output overshoot shall be less than or equal to 16 V.
• Maximum reverse voltage at charger output shall be less than or equal to 1 V.
• Maximum time to achieve steady state value for voltage and current (± 10 % tolerance) after load change (“no load/”normal load”) shall be less than or equal to 10 ms.
• Maximum duration of charging current overshoot peak value greater than 11 A shall be less than or equal to 5 ms.
• Maximum output voltage undershoot with a load current less or equal than 100 mA shall be 4,1 V.
Maximum duration of charging current overshoot is shown in Figure 1.
5.1.3 Test equipment
The following equipment is required to perform the test:
• oscilloscope;
• 6 k load as no load”;
• a suitable resistor to draw a 100 mA load current at the nominal output voltage;
• 3,0 V current sink type of load with 1,1 A current limit as “normal load”;
• AC power source (if charger is AC powered);
• DC power source (if charger is made for car environment).
5.1.4 Test method Proceed as follows.
a) Set the oscilloscope to measure voltage and current from the charger output.
b) Set the output of AC or DC power source to nominal value.
C) Measure the voltage and current values when the 6 k load and 3,0 V load (a load, which results 3,0 V charging voltage) are interchanged with a fast electronic switch (switching time less than 100 ps) at the charger output.
d) Measure the voltage undershoot when in 100 mA resistive load (a load, which draws 100 mA at nominal output voltage).
Repeat the test using minimum and maximum supply voltages specified to the charger (recommendation for AC powered chargers is nominal voltage ± 20 %).
The maximum allowed output ripple voltage with maximum output current in constant current mode is 300 mV RMS for output voltages Vout between2,5 V and 5,5 V. A sum of ripple voltages over the full frequency range 0 MHz to 1 MHz is 800 mV (peak-to-peak).
During the test all the measured V and I values shall be within the voltage 1 current window of the charger interface.
Maximum peak-to-peak ripple voltage is shown in Figure 2.
5.2.3 Test equipment
The following equipment is required to perform the test:
• oscilloscope which offers the possibility of selecting a measured frequency band;
• variable resistive load 0 k to 6 k Maximum stray capacitance of ripple test load (e.g. on-line testing) is 2 pF;
• AC power source (If charger is AC powered);
• DC power source (if charger is designed for car environment).
5.2.4 Test method Proceed as follows.
a) Set the output of AC or DC power source to nominal value. Connect charger to power supply and to variable load.
b) Set the oscilloscope to measure voltage from chargers output. Connect charger to variable load and set the load as 6 kr).
c) Set the oscilloscope to measure ripple voltage peak-to-peak value from frequency band O Hz to 20 Hz. Reduce resistance slowly until the output voltage is 1,5 V. Find the highest peak-to-peak value between maximum voltage and 1,5 V.
d) Set the oscilloscope to measure ripple voltage peak-to-peak value from frequency band 20 Hz to 200 Hz. Reduce resistance slowly until the output voltage is 1.5 V. Find the highest peak-to-peak value between maximum voltage and 1,5 V.
e) Set the oscilloscope to measure ripple voltage peak-to-peak value from frequency band 200 Hz to 20 kHz. Reduce resistance slowly until the output voltage is 1,5 V. Find the highest peak-to-peak value between maximum voltage and 1,5 V.
f) Set the oscilloscope to measure ripple voltage peak-to-peak value from frequency band 20 kHz to 1 MHz. Reduce resistance slowly until the output voltage is 1,5 V. Find the highest peak-to-peak value between maximum voltage and 1,5 V.
g) Set the variable resistance so that the output voltage is 5,5 V. Remove frequency band limitations from the oscilloscope. Set the oscilloscope to measure the root mean square (RMS) value of ripple voltage. Decrease resistance slowly so that the output voltage is 2,5 V. Find the largest RMS value between 5,5 V and 2,5 V.BS EN 62637-2 pdf download.