NCP1910GEVB ON Semiconductor, NCP1910GEVB Datasheet - Page 18

• Manufacturer Part Number: NCP1910GEVB
• Description: BOARD EVAL NCP1910DEMO-B-TLS
• Manufacturer: ON Semiconductor
• Series: -r

Specifications of NCP1910GEVB

• Design Resources: NCP1910 Schematic NCP1910GEVB BOM
• Main Purpose: DC/DC, Step Down
• Outputs And Type: 1, Non-Isolated
• Power - Output: -
• Voltage - Output: Adj down to 0.8V
• Current - Output: 3A
• Voltage - Input: 3 ~ 5.5 V
• Regulator Topology: Buck
• Frequency - Switching: 1MHz
• Board Type: Fully Populated
• Utilized Ic / Part: NCP1910
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: NCP1910GEVBOS

circuit, associating two individual cores performing the
functions of Continuous Conduction Mode (CCM) Power
Factor Correction (PFC) and LLC resonant control. These
cores interact together and implement handshake functions
in normal operating conditions but also when a fault appears.
Based on the ON Semiconductor proprietary high−voltage
technology, the LLC section can drive the high−side
MOSFET of the LLC half−bridge without the need of a
gate−drive transformer.
Power Factor Correction
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The NCP1910 represents a new generation of control
Compactness and Flexibility: the NCP1910 requires a
minimum of external components to perform a CCM
PFC operation. In particular, the circuit scheme
simplifies the PFC stage design. In addition, the circuit
offers some functions like the line brown−out detection
or true power limiting capability that enable the
optimization of the PFC design.
Low Consumption and Shutdown Capability: the
NCP1910 is optimized to consume a small current in all
operation modes. The consumed current is particularly
reduced during the start−up phase and in shutdown
mode so that the power losses are minimized when the
circuit is disabled. This feature helps meet stringent
stand−by low power specifications. Grounding the
Feed−back pin can force the circuit to enter standby but
the on/off pin can also serve this purpose.
Maximum Current Limit: the circuit permanently
senses the inductor current and immediately turns off
the power switch if it is higher than the set current
limit. The NCP1910 also prevents any turn on of the
power switch as long as the inductor current is not
below its maximum permissible level. This feature
protects the MOSFET from possible excessive stress
that could result from the switching of a current higher
than the one the power switch is dimensioned for. In
particular, this scheme effectively protects the PFC
stage during the start−up phase when large in−rush
currents charge the bulk capacitor.
Under−Voltage Protection for Open Loop
Protection: the circuit detects when the feed−back
voltage goes below than about 8% of the regulation
level. In this case, the circuit turns off and its
consumption drops to a very low value. This feature
protects the PFC stage from starting operation in case
of low ac line conditions or in case of a failure in the
feed−back network (i.e. bad connection). In case the
UVP circuitry is activated, the Power Good signal is
disabled and the LLC circuit stops immediately.
Fast Transient Response: given the low bandwidth of
the regulation block, the output voltage of PFC stages
may exhibit excessive over or under−shoots because of
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LLC Controller
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abrupt load or input voltage variations (e.g. at start up).
If the bulk voltage is too far from the regulation level:
Line Brown−Out Detection: the circuit detects low ac
line conditions and disables the PFC stage in this case.
This protection mainly protects the power switch from
the excessive stress that could damage it in such
conditions.
Over−Power Limitation: the NCP1910 computes the
maximum permissible current in dependence of the
average input voltage measured by the brown−out
block. It is the second OCP with a threshold that is line
dependent. When the circuit detects an excessive power
transfer, it resets the driver output immediately.
Redundant Over−Voltage Protection: As a redundant
safety feature, the NCP1910 offers a second latched
OVP whose input is available on OVP2 pin. If the
voltage on this pin is above the maximum allowable
voltage, the PFC and the LCC are latched off.
PFC Abnormal Protection: When PFC faces an
abnormal situation so that the bulk voltage is under
regulation longer than the allowable timing, the PFC
and LLC are latched off.
Frequency Foldback: in light output loading
conditions, the user has the ability to program a point
on the V
gradually reduced. This helps to maintain an adequate
efficiency on the PFC power stage alone.
Soft−Start: to offer a clean start−up sequence and limit
both the stress on the power MOSFET and the bulk
voltage overshoot, a 30 mA current source charges the
compensation network installed on V
makes V
Output Stage Totem Pole: the NCP1910 incorporates
a $1.0 A gate driver to efficiently drive TO220 or
TO247 power MOSFETs.
Wide frequency operation: the part can operate to a
frequency up to 500 kHz by connecting a resistive
network from R
maximum switching frequency whereas a second
resistor set the minimum frequency.
♦
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power switch as soon as V
threshold (105% of the regulation level). This is an
auto−recovery function.
drastically speeds up the regulation loop by its
internal 200 mA current source, activated when the
bulk voltage drops below 95% of its regulation level.
Over−Voltage Protection: NCP1910 turns off the
Dynamic Response Enhancer: NCP1910
CTRL
CTRL
pin where the oscillator frequency is
raise gradually.
t
pin to ground. One resistor sets the
bulk
exceeds the OVP
CTRL
pin and