Load Disconnection Function, 0.8A Step-up DC/DC Converters
XC9142 series are synchronous step-up DC/DC converters with a 0.3Ω(TYP.) N-channel driver transistor and a 0.4Ω(TYP.) synchronous P-channel switching transistor built-in. A highly efficient and stable current can be supplied up to 0.8A by reducing ON resistance of the built-in transistors.
The series are able to start operation under the condition which has 0.9V input voltage to generate 3.3V output voltage with a 100Ωload resistor, suitable for mobile equipment using only one Alkaline battery or one Nickel metal hydride battery.
The output voltage can be set from 1.8V to 5.5V (±2.0%) in steps of 0.1V.With the built-in oscillator, either 1.2MHz or 3.0MHz can be selected for suiting to your particular application.
During the devices enter stand-by mode, A, D type prevent the application malfunction by CL Discharge Function which can quickly discharge the electric charge at the output capacitor (CL). B, E type is able to drive RTC etc. by Bypass Switch Function to maintain continuity between the input and output. C, F type is able to connect in parallel with other power supplies by Load Disconnection Function which breaks continuity between the input and output.
Typical Application Circuit
|Input Voltage Range||0.65V～6.0V|
|Output Voltage Range||1.8V～5.5V(0.1V increments)|
|Oscillation Frequency||1.2MHz(Accuracy ±15%)
|Output Current||500mA@VOUT=5.0V, VBAT=3.3V(TYP.)
|Control Methods||PWM/PFM Auto Control|
|High Speed Transient||100mV@VOUT=3.3V, VBAT=1.8V
|Protection Circuits||Over Current Limit
Integral latch method(Types D,E,F)
Output short-circuit protection(Types D,E,F)
Load Disconnection Function(Types A,C,D,F)
CL Auto Discharge Function(Types A,D)
Bypass Switch Function(Types B,E)
|Operating Ambient Temperature||-40℃～+85℃|
|Environmentally Friendly||EU RoHS compliant, Pb free|
|Package||SOT-25||Number of Pins||5|
|Pcs/Reel||3,000||Package Size(mm)||2.8 x 2.9 x 1.3|
|Package||USP-6C||Number of Pins||6|
|Pcs/Reel||3,000||Package Size(mm)||1.8 x 2.0 x 0.6|
|Package||WLP-6-01||Number of Pins||6|
|Pcs/Reel||5,000||Package Size(mm)||1.28 x 1.08 x 0.4|
How does the CL discharge function work?
The function rapidly releases the charge remained in the CL capacitor to make the VOUT pin voltage zero. The VOUT pin voltage does not reach zero immediately after being turned off by the CE function due to the charge remained in the connected CL capacitor. While the charge in the CL capacitor is gradually reaching zero, the LSI continues operating and does not work with the CE pin signal, which may cause a malfunction. This is why the discharge is required when turning off the CE pin. A larger capacitance of the capacitor needs longer time to be discharged.
What does CL mean?
Load capacitor. Other companies often refer to it as COUT.
What is the standby current?
The current that flows through the IC in the standby mode. The standby mode means the state where the IC has been turned off by the CE function.
What does the FB product mean?
An IC for which any output voltage can be set by the reference voltage of the FB pins and the external dividing resistor. The output voltage is determined by the RFB1 and RFB2 values, using the following formula: VOUT = Vref × (RFB1 + RFB2)/RFB2
How does UVLO (under voltage lockout) work?
This circuit forcibly turns off the driver transistor when VIN drops below the UVLO voltage. If the input voltage recovers to the value which is equal to the specified value or more, UVLO will be released to resume the switching operation. It is resumed by the soft-start function. The paused state by UVLO is not the shutdown. The pulse output is stopped, but the internal circuit is operating.