FEATURES
●
Low noise output to avoid sensitivity of Can Tuner and DISH’s LNA dropping down
●Noise <+/-80mV@350MHz BWL ，●Noise <+/-50mV@20MHz BWL ●
Single chip solution on 700mVpp 22KHz EXTM with 10µs Trise/Tfall for less Transferring noise
●
LNB Voltages (2levels:14V and 19V)compatible with common standards,Push-pull output stage minimizes 14→19V and 19V →14V output transition times;
●External 22KHz EXTM input;
●
Integrated DC/DC BOOST converter and high efficiency (typ.90%)with integrated Power Mos-FET
● 1.0MHz Switch Frequency BOOST ●Integrated low Noise Linear Regulator ●
5.0V, 3.3V, 2.5V, 1.8V , 1.2and 1.05V logic compatible
●Internal Short,OCP,OTP,protection ●
eSOP8L package 、eTSSOP14L package
APPLICATIONS
●LNB Power supply For DVB-S/S2/ABS ●Digital STB
●
Satellite TV cards
I ntended for analog and digital satellite receivers/sat-TV,sat-OC cards,the
STI8035is a monolithic voltage regulator and interface IC,packaged in eSOP8EL ,specifically designed to provide the 14/19V power supply with high fficiency and the 22kHz EXTM signaling to the LNB
down-converter in the antenna dish or to the multi-switch box.
STI8035consists of a BOOST converter and a low-noise inear regulator along with the circuitry required for EXTM injection and pin controllable interface.The device makes the total LNB supply design simple,efficient and compact with low external component count
The external modulation input (EXTM pin)can accept a tome modulated DiSEqC command and transfer it symmetrically to the output to
强壮功
meet DiSEqC 1.x protocol
EFFICIENCY
650mA LNB-Power Supply &Control Voltage Regulator
GENERAL DESCRIPTION
TYPICAL APPLICATION
PIN DESCRIPTION (ESOP8)
PIN
DESCRIPTION
1Power Supply input
VOUT 2Output voltage for the LNB
BOOST 3BOOST converter output voltage sense,and internal LDO
terminal
VCP 4Charge Pump LDO supply
LX 5DC-DC switch connection,connects to inductor
EN 6low,the disabled.Setting EN =
张志琴
H_L 7input high:19V,EXTM 8
ELECTRICAL SPECFICATION
2、DISSIPATION RATINGS
3、RECOMMENDED OPERATING CONDITIONS
MIN 9-0.1-0.1H_L,EXTM_IN -0.1Ground(Exposed Pad)-0.1free-air temperature -40junction temperature -404、ELECTRICAL CHARACTERISTICS
Over operating free-air temperature range(unless otherwise noted)Symbol
CONDITIONS
Supply Voltage Operating supply voltage range
Input Under Lockout Threshold
Input Under Lockout Threshold Hysteresis Operating current
EN=”1”,VOUT=19V,22KHz EXTM Input
24mA Disable Supply Current ISDN EN=”0”
1.6
mA Output Voltage Output Voltage VOUT EN=”1”,H_L=”1”18.51919.9V EN=”1”,H_L=”0”13.6
1414.4
V Linear Regulator Drop Voltage
VDROP EN=”1”,
ILOAD=450mA 0.9V VIN Line Regulation RLINE
VIN=9~14V,VOUT=19V
4
40mV
VOUT output load regulation
RLOAD Iload=0~450mA,VOUT=19V
Slow Rate=255mA/us,CLOAD=0.2uF 30mV
Ripple and noise on VOUT output VNOISE
20MHz BWL 50mV 350MHz BWL 80mV Output Current limit ILIMIT
VOUT=19V or VOUT=14V 900
mA VOUT output short
180
mA
BOOST DC/DC Bost DC/DC
Switching Frequency FBOOST EN=”1”0.81 1.2MHz Switch On Resistance Rson ILOAD=450mA
120m ΩBOOST Maximum Duty DBST_M AX 80%BOOST Minimum On time
DBST_M IN 0%BOOST Current Limit
IBST_LI M
2.2
A
Short and Overload Protection Dynamic Overload ON
time
Ton
Output shorted to GND
65mS Dynamic Overload OFF
time
Toff
Output shorted to GND
1800mS Thermal Shutdown
Threshold
TSDN
160℃Thermal Shutdown
Hysteresis
TSDN_H Y 25
℃
EXTM
Input EXTM Frequency
Range
FEXTM
20
22KHz VOUT Output EXTM Amplitude,peak to peak VPP_EX TM
ILOAD=0~450mA,CLOAD=100nF
600
660
720
mV
VOUT output EXTM Duty
DEXTM ILOAD=0~450mA,CLOAD=570nF 50%VOUT output EXTM Rising Time
TRISE_T ON ILOAD=0~450mA,CLOAD=570nF 7.51012.5uS VOUT output EXTM Rising Time
TFALL_T ON ILOAD=0~450mA,CLOAD=570nF
7.510
12.5
uS EXTM High Logic Input VTON_I NH 0.95
V EXTM Low Logic Input VTON_I NL 0.55
V
EXTM Pin Input
Leakage Current ITON_LE AK
Pull down 2M RES
-3
H_L
H_L High Logic Input VHL_INH 0.95
V H_L Low Logic Input VHL_INL 0.55
V H_L Pin Input Leakage IHL_LEA K Input=1.2V
Pull down2M RES
-3
3
uA
EN
配料系统EN High Logic Input VEN_IN H 0.95 V EN Low Logic Input VEN_INL 0.55
V
EN PIN Maximum
Input Current
IEN_MA X
10uA
5、INTERNAL BLOCK DIAGRAM
6、FUNCTION DESCRIPTION旱榆
The STI8035single output LNB supply utilizes built-in DC/DC step-up converters,which operate from9V to14V and outputs the low noise voltage set by H-L pin,and accepts
a tome modulated DiSEqC command and transfers it symmetrically to the output to
meet DiSEqC1.x protocol.
DiSEqC Encoding
The EXTM accepts an externally modulated EXTM command and in turn modulates the VOUT symmetrically to meet the DiSEqC1.x and with few more external
components to meet DiSEqC2.0transmit protocol.Burst coding of the EXTM can be
accomplished due to the fast response of the EXTM pin.
仙人指路010
Linear Regulator
The output linear regulator is designed to source500mA continuous current and650mA
peak.In order to minimize the power dissipation,the output voltage of the internal
step-up converter is adjusted to allow the linear regulator to work at a minimum
dropout of1V typical(Load current=500mA)between the BOOST and VOUT pin.The BOOST pin is capable of withstanding a back voltage of27V.
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