XC9235/XC9236/XC9237
Series
■ELECTRICAL CHARACTERISTICS
XC9237A18Cxx, VOUT=1.8V, fOSC=1.2MHz, Ta=25℃
PARAMETER
SYMBOL
CONDITIONS
MIN.
TYP.
MAX. UNIT CIRCUIT
When connected to external components,
VIN=VCE=5.0V, IOUT=30mA
Output Voltage
VOUT
VIN
1.764
2.0
1.800 1.836
V
V
①
①
①
Operating Voltage Range
Maximum Output Current
-
-
6.0
-
VIN=VOUT(E)+2.0V, VCE=1.0V,
IOUTMAX
600
mA
When connected to external components (*9)
V
CE =VIN, VOUT=0V,
UVLO Voltage
VUVLO
1.00
1.40
1.78
V
②
Voltage which Lx pin holding “L” level (*1, *11)
VIN=VCE=5.0V, VOUT=VOUT(E)×1.1V
Supply Current
IDD
-
-
15
0
33
μA
μA
③
③
Stand-by Current
ISTB
VIN=5.0V, VCE=0V, VOUT=VOUT(E)×1.1V
1.0
When connected to external components,
VIN=VOUT(E)+2.0V, VCE =1.0V, IOUT=100mA
Oscillation Frequency
PFM Switching Current
fOSC
1020
120
1200
160
1380
200
kHz
mA
①
①
When connected to external components,
VIN=VOUT(E)+2.0V, VCE =VIN, IOUT=1mA (*12)
DTYLIMIT_PFM VCE=VIN=(C-1), IOUT=1mA (*12)
IPFM
PFM Duty Limit
Maximum Duty Cycle
Minimum Duty Cycle
200
%
%
%
①
②
②
DTYMAX
DTYMIN
VIN=VCE=5.0V, VOUT=VOUT(E)×0.9V
VIN=VCE=5.0V, VOUT=VOUT(E)×1.1V
When connected to external components,
100
-
-
-
-
0
Efficiency(*2)
EFFI
-
92
-
%
①
V
CE=VIN=VOUT(E)+1.2V, IOUT=100mA
Lx SW "H" ON Resistance 1
Lx SW "H" ON Resistance 2
Lx SW "L" ON Resistance 1
Lx SW "L" ON Resistance 2
Lx SW "H" Leak Current (*5)
Lx SW "L" Leak Current (*5)
Current Limit (*10)
RLxH
RLxH
RLxL
RLxL
ILeakH
ILeakL
ILIM
VIN=VCE=5.0V, VOUT=0V, ILx=100mA (*3)
VIN=VCE=3.6V, VOUT=0V, ILx=100mA (*3)
VIN=VCE=5.0V (*4)
-
0.35
0.42
0.45
0.52
0.01
0.01
1050
0.55
0.67
0.66
0.77
1.0
Ω
Ω
④
④
④
-
-
-
Ω
VIN=VCE=3.6V (*4)
-
Ω
VIN=VOUT=5.0V, VCE=0V, Lx=0V
VIN=VOUT=5.0V, VCE=0V, Lx=5.0V
VIN=VCE=5.0V, VOUT=VOUT(E)×0.9V (*8)
-
-
μA
μA
mA
⑤
⑤
⑥
1.0
900
1350
Output Voltage
Temperature Characteristics (VOUT・△topr)
△VOUT/
IOUT=30mA, -40℃≦Topr≦85℃
-
±100
-
ppm/
℃
①
③
③
V
OUT=0V, Applied voltage to VCE
,
CE "H" Voltage
CE "L" Voltage
VCEH
VCEL
0.65
VSS
-
-
6.0
0.25
V
Voltage changes Lx to “H” level (*11)
V
OUT=0V, Applied voltage to VCE ,
V
Voltage changes Lx to “L” level (*11)
When connected to external components,
PWM "H" Level Voltage
VPWMH
I
OUT=1mA (*6), Voltage which oscillation frequency
-
-
VIN - 1.0
V
①
becomes 1020 kHz≦fOSC≦1380kHz (*13)
When connected to external components,
IOUT=1mA (*6), Voltage which oscillation frequency
becomes fOSC<1020kHz (*13)
VIN
0.25
–
PWM "L" Level Voltage
VPWML
-
-
V
①
CE "H" Current
CE "L" Current
ICEH
ICEL
VIN=VCE=5.0V, VOUT=0V
VIN=5.0V, VCE=0V, VOUT=0V
- 0.1
- 0.1
-
-
0.1
0.1
μA
μA
⑤
⑤
When connected to external components,
Soft Start Time
Latch Time
tSS
0.5
1.0
1.0
-
2.5
ms
ms
①
⑦
V
CE=0V → VIN, IOUT=1mA
VIN=VCE=5.0V, VOUT=0.8×VOUT(E)
Short Lx at 1Ω resistance (*7)
,
tLAT
20.0
Sweeping VOUT, VIN=VCE=5.0V, Short Lx at
1Ω resistance, VOUT voltage which Lx becomes
“L” level within 1ms
Short Protection Threshold
Voltage
VSHORT
0.675 0.900 1.150
V
⑦
Test conditions: Unless otherwise stated, VIN=5.0V, VOUT(E)=Nominal Voltage
NOTE:
*1: Including hysteresis operating voltage range.
*2: EFFI = { ( output voltage×output current ) / ( input voltage×input current) }×100
*3: ON resistance (Ω)= (VIN - Lx pin measurement voltage) / 100mA
*4: R&D value
*5: When temperature is high, a current of approximately 10μA (maximum) may leak.
*6: The CE/MODE pin of the XC9237A series works also as an external switching pin of PWM control and PWM/PFM control. When the IC is in the operation,
control is switched to the automatic PWM/PFM switching mode when the CE/MODE pin voltage is equal to or greater than VIN minus 0.3V, and to the PWM
mode when the CE/MODE pin voltage is equal to or lower than VIN minus 1.0V and equal to or greater than VCEH
.
*7: Time until it short-circuits VOUT with GND via 1Ωof resistor from an operational state and is set to Lx=0V from current limit pulse generating.
*8: When VIN is less than 2.4V, limit current may not be reached because voltage falls caused by ON resistance.
*9: When the difference between the input and the output is small, some cycles may be skipped completely before current maximizes.
If current is further pulled from this state, output voltage will decrease because of P-ch driver ON resistance.
*10: Current limit denotes the level of detection at peak of coil current.
*11: “H”=VIN~VIN-1.2V, “L”=+0.1V~-0.1V
*12: XC9235 series exclude IPFM and DTYLIMIT_PFM because those are only for the PFM control’s functions.
*13: XC9235/9236 series exclude VPWMH and VPWML because those are only for the XC9237 series’ functions.
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