XC9223B081AR Torex Semiconductor Ltd, XC9223B081AR Datasheet - Page 10

• Manufacturer Part Number: XC9223B081AR
• Description: BUCK CONVERTER, 1MHZ SYNC., 9223
• Manufacturer: Torex Semiconductor Ltd

Specifications of XC9223B081AR

• Primary Input Voltage: 6V
• No. Of Outputs: 1
• Output Voltage: 6V
• Output Current: 1A
• Voltage Regulator Case Style: MSOP
• No. Of Pins: 10
• Operating Temperature Range: -40°C To +85°C
• Svhc: No SVHC
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

10/25
■OPERATIONAL EXPLANATION (Continued)
・External Clock Synchronization Function
MODE/SYNC
For protection against heat damage of the ICs, thermal shutdown function monitors chip temperature. The thermal
shutdown circuit starts operating and the driver transistor will be turned off when the chip’s temperature reaches 150
When the temperature drops to 130
initiate output startup operation.
The short-circuit protection circuit monitors FB voltage. In case where output is accidentally shorted to the Ground and
when the FB voltage decreases less than half of the FB voltage, the short-circuit protection operates to turn off and to
latch the driver transistor. In latch mode, the operation can be resumed by either turning the IC off and on via the CE pin,
or by restoring power supply to the V
When the V
caused by unstable operation of the internal circuitry. When the V
operation takes place. By releasing the U.V.L.O. function, the IC performs the soft-start function to initiate output startup
operation. The U.V.L.O. function operates even when the V
tens of ns.
A MODE/SYNC pin has two functions, a MODE switch and an input of external clock signal. The MODE/SYNC pin
operates as the PWM mode when applying high level of direct current and the PFM/PWM automatic switching mode by
applying low level of direct current, which is the same function as the normal MODE pin. By applying the external clock
signal (±25% of the internal clock signal, ON duty 25% to 75%), the MODE/SYNC pin switches to the internal clock signal.
Also the circuit will synchronize with the falling edge of external clock signal. While synchronizing with the external clock
signal, the MODE/SYNC pin becomes the PWM mode automatically. If the MODE/SYNC pin holds high or low level of the
external clock signal for several μs, the MODE/SYNC pin stops synchronizing with the external clock and switches to the
internal clock operation. (Refer to the chart below.)
<Thermal Shutdown>
<Short-Circuit Protection>
The detector block of the XC9223/9224 series detects a signal inputted from the V
open-drain).
<U.V.L.O. Circuit>
<MODE/SYNC>
<Voltage Detector>
XC9223/XC9224
50mV/div
VOUT
2V/div
2V/div
Lx
IN
pin voltage becomes 1.8V (TYP.) or lower, the driver transistor is forced OFF to prevent false pulse output
* When an input of MODE/SYNC is changed from “L” voltage into a clock signal of 1.2MHz and 50% duty.
External Clock Signal
1.2MHz Duty50%
1MHz
Operates by the
O
IN
internal clock
C or less after shutting of the current flow, the IC performs the soft start function to
pin.
Delay time to the external clock synchronization
Series
IN
pin voltage falls below the U.V.L.O. operating voltage for
IN
pin voltage becomes 2.0V (TYP.) or higher, switching
Synchronous with the
1.2MHz
external clock
1.0μs/div
DIN
pin by the V
DOUT
pin (N-ch
O
C.