HE9416
16V2A synchronous StepDown Converter
Ver10 Feb 252016 Page 1
Features
 Wide 33V to 16V Operating input Range
 2A Continuous Output Current
 No Schottky Diode Required
 600KHz Frequency Operation
 Builtin Over Current Limit
 Builtin Over Voltage Protection
 Internal Soft start
 Output Adjustable from 06V
 Integrated internal compensation
 Short Protection with HiccupMode
 Thermal Shutdown
 Available in SOT236 Package
 40℃ to +85℃ Temperature Range
Applications
 Digital Settop Box (STB)
 Tablet Personal Computer (Pad)
 FlatPanel Television and Monitor
 Digital Video Recorder (DVR)
 Portable Media Player (PMP)
 General Purposes
General Description
The HE9416 is a high frequency synchronous
rectified
stepdown switchmode converter with internal power
MOSFETs It offers a very compact solution to achieve a
2A continuous output current over a wide input supply
range with excellent load and line regulationThe HE9416
requires a minimal number of readily available external
components and is available in a space saving SOT236
package
Typical Application
Figure 1 Basic Application Circuit For VOUT5V
VOUT R1 R2
50V 50K 68K
33V 50K 11K
18V 50K 25K
15V 50K 333K
12V 50K 50K
10V 50K 75K
HE9416Ver10 Feb 252016 Page 2
System Block Diagram
Functional Description
Internal Regulator
The HE9416 is a current mode step down DCDC
converter that provides excellent transient response with
no extra external compensation components This device
contains an internal low resistance high voltage power
MOSFET and operates at a high 600K operating
frequency to ensure a compact high efficiency design
with excellent AC and DC performance
Error Amplifier
The error amplifier compares the FB pin voltage with the
internal FB reference (VFB) and outputs a current
proportional to the difference between the two This
output current is then used to charge or discharge the
internal compensation network to form the COMP voltage
which is used to control the power MOSFET current The
optimized internal compensation network minimizes the
external component counts and simplifies the control loop
design
Internal SoftStart
The softstart is implemented to prevent the converter
output voltage from overshooting during startup When
the chip starts the internal circuitry generates a softstart
voltage (SS) ramping up from 0V to 06V When it is lower
than the internal reference (REF) SS overrides REF so
the error amplifier uses SS as the reference When SS is
higher than REFREF regains control The SS time is
internally fixed to 15ms
Over Current Protection & Hiccup
The HE9416 has cyclebycycle over current limit when
the inductor current peak value exceeds the set current
limit threshold Meanwhile output voltage starts to drop
until FB is below the UnderVoltage (UV) threshold
typically 25 below the reference Once a UV is
triggered the TX9416 enters hiccup mode to periodically
restart the part This protection mode is especially useful
when the output is deadshort to ground The average
short circuit current is greatly reduced to alleviate the
thermal issue and to protect the regulator The TX9416
exits the hiccup mode once the over current condition is
removed
HE9416
16V2A synchronous StepDown ConverterVer10 Feb 252016 Page 3
Startup and Shutdown
If both VIN and EN are higher than their appropriate
thresholds the chip starts The reference block starts first
generating stable reference voltage and currents and
then the internal regulator is enabled The regulator
provides stable supply for the remaining circuitries Three
events can shut down the chip EN low VIN low and
thermal shutdown In the shutdown procedure the
signaling path is first blocked to avoid any fault triggering
The COMP voltage and the internal supply rail are then
pulled down The floating driver is not subject to this
shutdown command
Pin Description
PIN NAMEFUNCTION
1 BS Bootstrap A capacitor connected between SW and BST pins is
required to form a floating supply across the highside switch
driver
2 GND GROUNDPin
3 FB Adjustable Version Feedback input Connect FB to the center
point of the external resistor divider
4 EN Drive this pin to a logichigh to enable the IC Drive to a logiclow
to disable the IC and enter micropower shutdown mode
5 IN Power Supply Pin
6 SW Switching Pin
Pin Configuration
(SOT236)
HE9416
16V2A synchronous StepDown ConverterVer10 Feb 252016 Page 4
Absolute Maximum Ratings
Vin EN Voltage ·········································································································································03V to 17V
Operating Temperature Range ·················································································································40℃to +85℃
FB Voltages················································································································································03 to 6V
Lead Temperature (Soldering 10s) ·········································································································· +300℃
SW Voltage ·················································································································································03Vto VIN+05V)
Storage Temperature Range·····················································································································65℃to 150℃
BS Voltage ··········································································································(Vsw03) to (Vsw+5V)
Electrical Characteristics
(VIN12V Vout5VTA 25℃ unless otherwise noted)
Parameter Conditions MIN TYP MAX unit
Input Voltage Range 33 16 V
Supply Current in Operation VEN30V VFB11V 04 06 mA
Supply Current in Shutdown VEN 0 or EN GND 4 uA
Regulated Feedback Voltage TA 25℃ 4V≤VIN ≤18V 0588 06 0612 V
HighSide Switch
OnResistance
100 mΩ
LowSide Switch
OnResistance
70 mΩ
HighSide Switch Leakage
Current
VEN0V VSW0V 0 10 uA
Upper Switch Current Limit Minimum Duty Cycle 3 A
Oscillation Frequency 06 MHz
Maximum Duty Cycle VFB06V 92
Minimum OnTime 60 nS
Minimum OffTime 90 nS
Thermal Shutdown 160 ℃
Thermal Hysteresis 20 ℃
HE9416
16V2A synchronous StepDown ConverterVer10 Feb 252016 Page 5
Typical Performance Characteristics
EFFICIENCY VS OUTPUT CURRENT (VOUT5V) OUTPUT VOLTAGE VS OUTPUTCURRENT (VOUT5V)
STEADYSTATE OPERATION
(VIN12VVOUT12VIOUT100mA)
STEADYSTATE OPERATION
(VIN12VVOUT12VIOUT1000mA)
LOAD TRANSIENT RESPONSE
(VIN12VVOUT12VIOUT1001000mA1AuS)
STRAT UP
(VIN12VVOUT12V)
HE9416
16V2A synchronous StepDown ConverterVer10 Feb 252016 Page 6
Marking Information
Applications Information
Setting the Output Voltage
HE9416 require an input capacitor an output capacitor
and an inductor These components are critical to the
performance of the device HE9416 are internally
compensated and do not require external components to
achieve stable operation The output voltage can be
programmed by resistor divider
Selecting the Inductor
The recommended inductor values are shown in the
Application Diagram It is important to guarantee the
inductor core does not saturate during any foreseeable
operational situation The inductor should be rated to
handle the peak load current plus the ripple current Care
should be taken when reviewing the different saturation
current ratings that are specified by different
manufacturers Saturation current ratings are typically
specified at 25 ℃ so ratings at maximum ambient
temperature of the application should be requested from
the manufacturer
Pin1 sign
SOT236
KM 6 Y M
K：降压系列
M：Vin36～16V
Part Number(TX94166)
Y：Year
(920090201012011）
M：Month(190AB)
HE9416
16V2A synchronous StepDown ConverterVer10 Feb 252016 Page 7
OSCLin
outinout
fIV
VVVL 
 )(
Where ΔIL is the inductor ripple current Choose inductor
ripple current to be approximately 30 if the maximum
load current 2A The maximum inductor peak current is
2)(
L
LOADMAXL
III 
Under light load conditions below 100mA larger
inductance is recommended for improved efficiency
Selecting the Output Capacitor
Special attention should be paid when selecting these
components The DC bias of these capacitors can result
in a capacitance value that falls below the minimum value
given in the recommended capacitor specifications table
The ceramic capacitor’s actual capacitance can vary with
temperature The capacitor type X7R which operates
over a temperature range of −55℃ to +125℃ will only
vary the capacitance to within ±15 The capacitor type
X5R has a similar tolerance over a reduced temperature
range of − 55 ℃ to +85 ℃ Many large value ceramic
capacitors larger than 1uF are manufactured with Z5U or
Y5V temperature characteristics Their capacitance can
drop by more than 50 as the temperature varies from
25℃ to 85℃ Therefore X5R or X7R is recommended
over Z5U and Y5V in applications where the ambient
temperature will change significantly above or below
25℃
Tantalum capacitors are less desirable than ceramic for
use as output capacitors because they are more
expensive when comparing equivalent capacitance and
voltage ratings in the 047uF to 44uF range Another
important consideration is that tantalum capacitors have
higher ESR values than equivalent size ceramics This
means that while it may be possible to find a tantalum
capacitor with an ESR value within the stable range it
would have to be larger in capacitance (which means
bigger and more costly) than a ceramic capacitor with the
same ESR value It should also be noted that the ESR of
a typical tantalum will increase about 21 as the
temperature goes from 25℃ down to −40℃ so some
guard band must be allowed
PCB Layout Guide
PCB layout is very important to achieve stable operation It
is highly recommended to duplicate EVB layout for
optimum performance If change is necessary please
follow these guidelines and take Figure 4 for reference
1) Keep the path of switching current short and minimize
the loop area formed by Input capacitor highside
MOSFET and lowside MOSFET
2) Bypass ceramic capacitors are suggested to be put
close to the Vin Pin
3) Ensure all feedback connections are short and direct
Place the feedback resistors and compensation
components as close to the chip as possible
4) VOUT SW away from sensitive analog areas such as
FB
5) Connect IN SW and especially GND respectively to a
large copper area to cool the chip to improve thermal
performance and longterm reliability
6) An example of 2layer PCB layout is shown in Figure 4
for reference
HE9416
16V2A synchronous StepDown ConverterVer10 Feb 252016 Page 8
Package Description
6pin SOT236 Outline Dimensions
HE9416
16V2A synchronous StepDown Converter

《香当网》用户分享的内容，不代表《香当网》观点或立场，请自行判断内容的真实性和可靠性！
该内容是文档的文本内容，更好的格式请下载文档