W
[email protected]
- Jan 1, 1970
- 0
Hello everyone,
I'm new to electronics design, when building DC-DC converter to charge
cellphone, I noticed it did not work. I tried MAX1797, I can get the
output voltage: +5.1V, which is good for Moto RAZR, but for some
reason, I suspect the output current is not good enough. From the spec,
it appears the converter can generate typical Iout = 0.55A.
The link to this IC:
http://www.maxim-ic.com/quick_view2.cfm/qv_pk/2377
I did not add any other circuit, just used the circuit from Evaluation
kit and adjust R1 and R2 to get Vo=+5.1V.
http://www.maxim-ic.com/quick_view2.cfm?qv_pk=2512
I can measure the current to the cellphone, it's around 5mA instead of
around several hundreds of mA (i.e. 500mA), the although the voltage is
+5.1 as expected.
I connect the output Vout to cellphone's charging Pin (Vbus of MiniUSB)
and also connected GND to cellphone GND. I can hear cellphone is
detecting a charger (a beep sound), but it did not charge, if I remove
my circuit, got beep again which means "charger" removing detected.
Anyone has idea why it did not work?
Thanks,
Gary
I'm new to electronics design, when building DC-DC converter to charge
cellphone, I noticed it did not work. I tried MAX1797, I can get the
output voltage: +5.1V, which is good for Moto RAZR, but for some
reason, I suspect the output current is not good enough. From the spec,
it appears the converter can generate typical Iout = 0.55A.
The link to this IC:
http://www.maxim-ic.com/quick_view2.cfm/qv_pk/2377
I did not add any other circuit, just used the circuit from Evaluation
kit and adjust R1 and R2 to get Vo=+5.1V.
http://www.maxim-ic.com/quick_view2.cfm?qv_pk=2512
I can measure the current to the cellphone, it's around 5mA instead of
around several hundreds of mA (i.e. 500mA), the although the voltage is
+5.1 as expected.
I connect the output Vout to cellphone's charging Pin (Vbus of MiniUSB)
and also connected GND to cellphone GND. I can hear cellphone is
detecting a charger (a beep sound), but it did not charge, if I remove
my circuit, got beep again which means "charger" removing detected.
Anyone has idea why it did not work?
Thanks,
Gary