RT5070
Single Output LNB Supply and Control Voltage Regulator
General Description
The RT5070 is a highly integrated voltage regulator
and interface IC, specifically design for supplying
power and control signals from advanced satellite
set-top box (STB) modules to the LNB down-converter
in the antenna dish or to the multi-switch box.
The device is consists of the independent current-mode
boost controller and low dropout linear regulator for the
LNB power.
The RT5070 has fault protection (over-current,
over-temperature and under-voltage lockout).
The RT5070 are available in a SOP-8 (Exposed Pad)
package to achieve optimized solution for thermal
dissipation.
Features
Wide Input Supply Voltage Range : 8V to 16V
Output Current Limit of 550mA with 45ms Timer
Low Noise LNB Output Voltage (13.3V and 18.3V
by SEL Pin)
±3% High Accuracy for 0mA to 500mA Current
Output
Push-Pull Output Stage Minimizes 13.3V to
18.3V and 18.3V to 13.3V Output Transition Time
Output Short Circuit Protection
Over-Temperature Protection
Applications
Ordering Information
RT5070
Package Type
SP : SOP-8 (Exposed Pad-Option 2)
Lead Plating System
G : Green (Halogen Free and Pb Free)
Note :
Richtek products are :
LNB Power Supply and Control for Satellite Set-Top
Box
Analog and Digital Satellite Receivers/Satellite TV,
Satellite PC cards
Pin Configurations
(TOP VIEW)
LNB
BOOST
LX
VIN
2
3
4
8
7
GND
FAULT
SEL
EN
GND
9
6
5
RoHS compliant and compatible with the current
requirements of IPC/JEDEC J-STD-020.
SOP-8 (Exposed Pad)
Suitable for use in SnPb or Pb-free soldering
processes.
Simplified Application Circuit
L1
VIN
C
IN1
LX
VIN
C
IN2
Max. 550mA
EN
SEL
3.3V
R1
FAULT
GND
D5
V
LNB
D2
C
LNB
D4
BOOST
D3
C
BST
D1
RT5070
LNB
Copyright © 2016 Richtek Technology Corporation. All rights reserved.
is a registered trademark of Richtek Technology Corporation.
DS5070-01
November 2016
www.richtek.com
1
RT5070
Marking Information
RT5070
GSPYMDNN
RT5070GSP : Product Number
YMDNN : Date Code
Functional Pin Description
Pin No.
1
2
3
4
5
6
7
Pin Name
LNB
BOOST
LX
VIN
EN
SEL
FAULT
Output voltage for LNB.
Boost output and tracking supply voltage to LNB.
Switching node of DC-DC boost converter.
Power supply input.
LNB output enable.
LNB output voltage selection pin (Low is for 13.3V, high is for 18.3V).
Fault detection pin. Pull to 3.3V by 4.7k resistor.
Ground. The exposed pad must be soldered to a large PCB and connected
to GND for maximum power dissipation.
Pin Function
8, 9 (Exposed Pad) GND
Function Block Diagram
LX
VIN
OCP1
UVLO
BOOST
VR1
VFB1
Error
Amp
PWM
Controller
RF1
RF2
EN
Oscillator
OSC
2-steps
Voltage
Setting
VD2
Linear
Regulator
Dynamic
Dropout
Control
LNB
VUD
DAC
SEL
OCP2
Logic
Bandgap
Reference
VD1
FAULT
OTP
VR1
Reference
Voltage
GND
Copyright © 2016 Richtek Technology Corporation. All rights reserved.
is a registered trademark of Richtek Technology Corporation.
www.richtek.com
2
DS5070-01
November 2016
RT5070
Operation
The RT5070 integrates a current mode boost converter
and linear regulator. Use the SEL pin to control the
LNB voltage and the boost converter track is at least
greater 850mV than LNB voltage. The boost converter
is the high efficiency PWM architecture with 700kHz
operation frequency. The linear regulator has the
capability to source current up to 550mA during
continuous operation. All the loop compensation,
current sensing, and slope compensation functions are
provided internally.
OCP
Both the boost converter and the linear regulator have
independent current limit. In the boost converter
(OCP1), this is achieved through cycle-by-cycle
internal current limit (typ. 3A). In the linear regulator
(OCP2), when the linear regulator exceeds OCP more
than 48ms, the LNB output will be disabled and re-start
after 1.8s.
OTP
When the junction temperature reaches the critical
temperature (typically 150C), the boost converter and
the linear regulator are immediately disabled.
UVLO
The UVLO circuit compares the VIN with the UVLO
threshold (7.7V rising typically) to ensure that the input
voltage is high enough for reliable operation. The
350mV (typ.) hysteresis prevents supply transients
from causing a shutdown.
PWM Controller
The loop compensation, current sensing, and slope
compensation functions are provided internally.
Copyright © 2016 Richtek Technology Corporation. All rights reserved.
is a registered trademark of Richtek Technology Corporation.
DS5070-01
November 2016
www.richtek.com
3
RT5070
Absolute Maximum Ratings
(Note 1)
Supply Input Voltage, VIN -------------------------------------------------------------------------------------------
0.3V
to 28V
Output Voltage LNB, LX and BOOST Pins ---------------------------------------------------------------------
0.3V
to 30V
Others Pin to GND ----------------------------------------------------------------------------------------------------
0.3V
to 6V
Power Dissipation, P
D
@ T
A
= 25C
SOP-8 (Exposed pad) ------------------------------------------------------------------------------------------------
3.44W
Package Thermal Resistance
(Note 2)
SOP-8 (Exposed pad),
JA
------------------------------------------------------------------------------------------
29C/W
SOP-8 (Exposed pad),
JC
------------------------------------------------------------------------------------------
2C/W
Lead Temperature (Soldering, 10 sec.) --------------------------------------------------------------------------
260C
Junction Temperature ------------------------------------------------------------------------------------------------
150C
Storage Temperature Range ---------------------------------------------------------------------------------------
65C
to 150C
ESD Susceptibility
(Note 3)
HBM (Human Body Model) -----------------------------------------------------------------------------------------
2kV
Recommended Operating Conditions
(Note 4)
Supply Input Voltage -------------------------------------------------------------------------------------------------
8V
to 16V
Ambient Temperature Range---------------------------------------------------------------------------------------
40C
to 85C
Junction Temperature Range --------------------------------------------------------------------------------------
40C
to 125C
Electrical Characteristics
(V
IN (typ.)
= 12V, V
IN
= 8V to 16V, T
A
= 25C, unless otherwise specified)
Parameter
General
LNB Output Accuracy,
Load and Line Regulation
Supply Current
Symbol
Test Conditions
Min
Typ
Max
Unit
E
RR
I
IN_OFF
I
IN_ON
Relative to selected V
LNB
target level,
I
LOAD
= 0 to 450mA
EN = 0, LNB output disabled
EN = 1, VLNB = 18.3V, Tone = 0V
I
LOAD
= 450mA
3
--
--
--
600
--
0.3
10
150
700
3
0.85
3
3
20
38
3
0.5
%
mA
18
300
800
--
--
10
10
--
76
m
kHz
A
V
ms
ms
mV
PP
mV
Boost Switch On
Resistance
Switching Frequency
Switch Current Limit
Linear Regulator Voltage
Drop
Output Voltage Rise Time
Output Voltage Pull-Down
Time
R
DS(ON)
f
SW
I
LIMSW
V
DROP
T
R_LNB
T
F_LNB
V
IN
= 10V, V
OUT
= 20.5V
V
BOOST
-V
LNB
, I
LOAD
= 450mA
For V
LNB
= 13.3V18.3V,
C
TCA P
= 100nF, I
LOAD
= 450mA
For V
LNB
= 18.3V13.3V,
C
LOAD
= 100nF, I
LOAD
= 0mA
20MHz bandwidth limit (GBD)
--
--
--
--
--
--
Ripple and Noise on LNB
V
RIP_PP
Output
Load Regulation
V
OUT_LOAD
V
OUT
= 13.3V, I
OUT
= 50mA to 450mA
Copyright © 2016 Richtek Technology Corporation. All rights reserved.
is a registered trademark of Richtek Technology Corporation.
www.richtek.com
4
DS5070-01
November 2016
RT5070
Parameter
Symbol
Test Conditions
V
OUT
= 18.3V, I
OUT
= 50mA to 450mA
V
IN
= 9 to 14V, V
OUT
= 13.3V,
I
OUT
= 50mA
V
IN
= 9 to 14V, V
OUT
= 18.3V,
I
OUT
= 50mA
V
LNB
= 13.3V/18.3V
V
LNB
short to GND
V
LNB
short to GND (GBD)
V
IN
falling
V
IN
rising
Min
--
Typ
45
--
--
Max
90
10
mV
10
Unit
10
10
Line Regulation
V
OUT_LINE
Protection
Output Over-Current Limit
Output Over-Current
Disable Time
Output Over-Current
Disable Time
I
LIM_LNB1
T
DIS_ON
T
DIS_OFF
500
--
--
--
--
--
--
--
550
45
1800
7.35
7.7
350
140
15
650
--
--
--
8
--
--
--
mA
ms
ms
V
V
mV
o
o
VIN Under-Voltage Lockout
V
UVLO
Threshold
VIN Turn On Threshold
V
IN_TH
VIN Under-Voltage Lockout
V
UVLOHYS
Hysteresis
OTP Threshold
OTP Hysteresis
ENABLE, SEL Pins
V
EN_H
EN Logic Input
V
EN_L
EN Input Leakage
SEL Logic Input
V
SEL_L
SEL Input Leakage
I
SELLKG
I
ENLKG
V
SEL_H
T
OTP
T
OTPHYS
C
C
1.2
--
--
1.2
--
--
--
--
5
--
--
5
--
V
0.4
10
--
V
0.4
10
A
A
Note 1.
Stresses beyond those listed “Absolute Maximum Ratings” may cause permanent damage to the device. These are
stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the
operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions may affect
device reliability.
Note 2.
JA
is measured at T
A
= 25C on a high effective thermal conductivity four-layer test board per JEDEC 51-7.
JC
is
measured at the exposed pad of the package.
Note 3.
Devices are ESD sensitive. Handling precaution recommended.
Note 4.
The device is not guaranteed to function outside its operating conditions.
Note 5.
Operation at V
IN
= 16V may be limited by power loss in the linear regulator.
Copyright © 2016 Richtek Technology Corporation. All rights reserved.
is a registered trademark of Richtek Technology Corporation.
DS5070-01
November 2016
www.richtek.com
5
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