OPTIREG™ switcher TLS4120D0EPV
2.8 MHz synchronous step down regulator
Features
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2 A step down regulator
Input voltage from 3.7 V to 35 V
Adjustable output voltage 3.0 V to 10.0 V
±1.5% feedback voltage accuracy in PWM mode
Ultra low current consumption 31 µA
Integrated high side and low side power MOSFETs
Peak current mode PWM regulation
Light load PFM mode with improved efficiency
Switching frequency range: 320 kHz to 560 kHz or 1.6 MHz to 2.8 MHz
100% duty cycle operation
Synchronization input
Spread spectrum frequency modulation for improved EMI performance
Soft-start function
Integrated compensation network
Output discharge function in disabled state
Ultra low current consumption in disabled state (typically 1 µA)
Undervoltage monitoring
Overvoltage monitoring
Overcurrent protection and overload protection
Input undervoltage shutdown
Wide temperature range Tj = -40°C to 150°C
Green Product (RoHS compliant)
Potential applications
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Body
ADAS
Infotainment, telematics
Navigation
Product validation
Qualified for automotive applications. Product validation according to AEC-Q100.
Datasheet
Please read the Important Notice and Warnings at the end of this document
www.infineon.com/OPTIREG-switcher
Rev. 1.02
2021-02-05
OPTIREG™ switcher TLS4120D0EPV
2.8 MHz synchronous step down regulator
Description
Description
The OPTIREG™ switcher TLS4120D0EPV is a 2.8 MHz synchronous step down regulator especially designed
for automotive applications. The device has a current capability of 2 A, adjustable output voltage and
a feedback voltage accuracy of ±1.5% in PWM mode. The integrated power stages, soft-start feature and
integrated compensation network reduce the required amount of external components and thus system costs
and board space. The wide input voltage range and a 100% duty cycle operation mode make the device
suitable for battery cranking scenarios in automotive applications. The wide switching frequency range allows
the selection of appropriate coils and capacitors. The switching frequency can be synchronized to an external
clock signal. Spread spectrum frequency modulation can be activated to improve the EMI performance in PWM
operation. The device offers low current consumption in PFM mode at light loads to optimize efficiency. The
TLS4120D0EPV can detect undervoltage and overvoltage conditions of the output voltage and indicates this
with the reset output signal. Overcurrent and overload protections avoid excessive current to protect the device
during short circuit conditions at the buck converter output. The integrated thermal shutdown feature protects
the device from overheating. The enhanced PG-TSDSO-14 exposed pad package offers advantageous thermal
performance in the application.
Type
Package
Marking
TLS4120D0EPV
PG-TSDSO-14
4120D0V
Datasheet
2
Rev. 1.02
2021-02-05
OPTIREG™ switcher TLS4120D0EPV
2.8 MHz synchronous step down regulator
Table of contents
Table of contents
Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Potential applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Product validation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1
Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2
Table of contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1
Block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2
2.1
2.2
Pin configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Pin assignment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6
Pin definitions and functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
3
3.1
3.2
3.3
General product characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Absolute maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Functional range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Thermal resistance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
4
4.1
4.1.1
4.1.1.1
4.1.1.2
4.1.1.3
4.1.1.4
4.1.2
4.1.2.1
4.1.2.2
4.1.3
4.1.3.1
4.1.3.2
4.1.3.3
4.2
4.3
Buck regulator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Functional description buck regulator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Regulation loop and operation modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
PWM (Pulse Width Modulation) mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
PFM (Pulse Frequency Modulation) mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Continuous conduction mode and discontinuous conduction mode . . . . . . . . . . . . . . . . . . . . .12
High duty cycle operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Power-up and power-down control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Startup procedure with soft-start . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Active output discharge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Protection features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Overcurrent protection and overload protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15
Input undervoltage shutdown . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Overtemperature protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15
Electrical characteristics buck regulator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Typical performance characteristics buck regulator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
5
5.1
5.1.1
5.1.2
5.2
5.3
Oscillator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Functional description oscillator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Synchronization input . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27
Spread spectrum . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Electrical characteristics oscillator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Typical performance characteristics oscillator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
6
Current consumption and enable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31
Datasheet
3
Rev. 1.02
2021-02-05
OPTIREG™ switcher TLS4120D0EPV
2.8 MHz synchronous step down regulator
Table of contents
6.1
6.2
6.3
Functional description current consumption and enable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Electrical characteristics current consumption and enable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Typical performance characteristics current consumption and enable . . . . . . . . . . . . . . . . . . . . . . . 32
7
7.1
7.2
7.3
Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Functional description reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Electrical characteristics reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Typical performance characteristics reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
8
8.1
8.2
8.3
8.4
Application information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Output voltage adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
Feedforward capacitor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
Layout recommendations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Additional information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .40
9
Package information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Disclaimer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
Datasheet
4
Rev. 1.02
2021-02-05
OPTIREG™ switcher TLS4120D0EPV
2.8 MHz synchronous step down regulator
Block diagram
1
Block diagram
VS
VS
EN
Enable
Overtemperature
shutdown
UVLO
Internal
supply
Bandgap
reference
FREQ
Control loop
+ driver
SYNC
SW
Oscillator
PGND
SSON
Spread
spectrum
FB
Soft-start
ramp
generator
RT
Reset
RO
AGND
Figure 1
Datasheet
Block diagram
5
Rev. 1.02
2021-02-05
OPTIREG™ switcher TLS4120D0EPV
2.8 MHz synchronous step down regulator
Pin configuration
2
Pin configuration
2.1
Pin assignment
FREQ
SYNC
RO
AGND
EN
VS
VS
1
2
3
4
5
6
7
TSDSO-14
14
13
12
11
10
9
8
Figure 2
Pin configuration
2.2
Pin definitions and functions
FB
RT
SSON
SW
SW
PGND
PGND
Pin
Symbol
Function
1
FREQ
Frequency selection input:
Connect this pin to GND via resistor for frequency selection.
Leave this pin open to set the default high switching frequency.
Connect this pin to GND to set the default low switching frequency.
2
SYNC
Synchronization input:
Connect this pin to external clock to synchronize the switching frequency.
If this pin is not used, then connect it to GND.
3
RO
Reset output:
Open drain reset output. Provides the reset output signal.
If the reset feature is used, then connect this pin via external resistor to VCC or to an external
pull-up voltage.
If the reset feature is not used, then leave this pin open.
4
AGND
Analog ground:
Connect this pin to GND using a low inductive, broad PCB trace.
5
EN
Enable input:
This pin has an integrated pull-down resistor.
"High" enables the device.
"Low" disables the device.
6, 7
VS
Supply voltage input:
Connect this pin to supply voltage.
Short pins 6 and 7 at the PCB.
8, 9
PGND
Power ground:
Connect this pin directly to GND using a low inductive, broad PCB trace.
Short pins 8 and 9 at the PCB.
10, 11 SW
Datasheet
Regulator switch node:
6
Rev. 1.02
2021-02-05
OPTIREG™ switcher TLS4120D0EPV
2.8 MHz synchronous step down regulator
Pin configuration
Pin
Symbol
Function
Connect this pin to the buck converter power inductor.
Short pins 10 and 11 at the PCB.
12
SSON
Spread spectrum enable input:
This pin has an integrated pull-down resistor.
"High" enables spread spectrum.
"Low" disables spread spectrum.
13
RT
Reset configuration input:
Connect this pin via a resistor to GND to adjust the reset delay time and the reset
undervoltage threshold.
Connect this pin to GND, if the reset function is not needed or to configure the default reset
delay time and default undervoltage reset threshold.
14
FB
Feedback input:
Feedback input to the regulator. Connect this pin to the feedback resistor divider tap (see
Output voltage adjustment).
–
Exposed Connect the exposed pad to a heatsink area and to GND with low inductive and broad PCB
pad
trace.
Datasheet
7
Rev. 1.02
2021-02-05
OPTIREG™ switcher TLS4120D0EPV
2.8 MHz synchronous step down regulator
General product characteristics
3
General product characteristics
3.1
Absolute maximum ratings
Table 1
Absolute maximum ratings1)
Tj = -40°C to 150°C; all voltages with respect to ground (unless otherwise specified)
Parameter
Symbol
Values
Min.
Typ.
Max.
Unit Note or
condition
Number
Voltages
Enable input
VEN
-20
–
35
V
–
P_3.1.1
Enable input
VEN,dyn
-20
–
42
V
2) Transients
P_3.1.2
Synchronization input
VSYNC
-0.3
–
6
V
–
P_3.1.3
Spread spectrum enable input
VSSON
-0.3
–
6
V
–
P_3.1.4
Frequency selection
VFREQ
-0.3
–
6
V
–
P_3.1.5
Reset output
VRO
-0.3
–
6
V
–
P_3.1.6
Reset configuration
VRT
-0.3
–
6
V
–
P_3.1.7
Feedback input
VFB
-0.3
–
1.5
V
–
P_3.1.8
Buck switch output
VSW
-0.3
–
VVS + 0.3
V
Minimum -2.0 V
in transient
condition (single
event < 15 ns)
P_3.1.9
Supply voltage input
VVS
-0.3
–
35
V
–
P_3.1.10
Supply voltage input
VVS,dyn
-0.3
–
42
V
2) Transients
P_3.1.11
Power GND
VPGND
-0.3
–
0.3
V
–
P_3.1.12
Analog GND
VAGND
-0.3
–
0.3
V
–
P_3.1.13
Junction temperature
Tj
-40
–
150
°C
–
P_3.1.14
Storage temperature
Tstg
-55
–
150
°C
–
P_3.1.15
VESD,HBM
-2
–
2
kV
3) HBM
P_3.1.16
V
4) CDM
P_3.1.17
present on this
pin
present on this
pin
Temperatures
ESD susceptibility
ESD susceptibility to GND
ESD susceptibility to GND
1
2
3
4
VESD,CDM
-500
–
500
Not subject to production test, specified by design.
Transients between 35 V and 42 V can be tolerated for a total lifetime duration shorter than 48 s.
ESD susceptibility, Human Body Model (HBM) according to ANSI/ESDA/JEDEC JS-001 (1.5 kΩ, 100 pF).
ESD susceptibility, Charged Device Model (CDM) according to JEDEC JESD22-C101.
Datasheet
8
Rev. 1.02
2021-02-05
OPTIREG™ switcher TLS4120D0EPV
2.8 MHz synchronous step down regulator
General product characteristics
Table 1
Absolute maximum ratings1) (continued)
Tj = -40°C to 150°C; all voltages with respect to ground (unless otherwise specified)
Parameter
Symbol
Values
Min.
ESD susceptibility corner pins 1, 7, 8,
14 to GND
VESD,CDM,C -750
Typ.
–
Max.
750
Unit Note or
condition
4) CDM
V
Number
P_3.1.18
Notes:
1.
Stresses above the ones listed here may cause permanent damage to the device. Exposure to absolute
maximum rating conditions for extended periods of time may affect device reliability.
2.
Integrated protection functions are designed to prevent IC destruction under fault conditions described in
the data sheet. Fault conditions are considered as outside the normal operating range. Protection functions
are not designed for continuous repetitive operation.
3.2
Functional range
Table 2
Functional range
Tj = -40°C to 150°C; all voltages with respect to ground (unless otherwise specified)
Parameter
Symbol
Values
Min.
Typ.
Unit
Note or condition
Number
5) Minimum value
P_3.2.1
Max.
Supply voltage decreasing
VVS,dec
3.7
–
35
V
Supply voltage increasing
VVS,inc
6.0
–
35
V
Minimum value
represents startup
condition
P_3.2.2
Enable input
VEN
0
–
35
V
–
P_3.2.3
Output voltage adjust range
VCC
3.0
–
10
V
–
P_3.2.6
SYNC input voltage
VSYNC
0
–
5.2
V
–
P_3.2.9
Reset output voltage
VRO,hi
0
–
5.2
V
6)
P_3.2.12
Output current
ICC
0
–
2
A
–
P_3.2.14
Junction temperature
Tj
-40
–
150
°C
–
P_3.2.15
1
4
5
6
represents low
battery voltage
condition (cranking)
Not subject to production test, specified by design.
ESD susceptibility, Charged Device Model (CDM) according to JEDEC JESD22-C101.
With 3.7 V < VVS < 6 V, a reduced performance of parameter settings applies to feedback voltage accuracy,
synchronization and the reset function.
Allowed pull-up voltage applied via pull-up resistance to pin RO.
Datasheet
9
Rev. 1.02
2021-02-05
OPTIREG™ switcher TLS4120D0EPV
2.8 MHz synchronous step down regulator
General product characteristics
Note:
Within the functional or operating range, the IC operates as described in the circuit description. The
electrical characteristics are specified within the conditions given in the electrical characteristics
table.
3.3
Thermal resistance
Table 3
Thermal resistance7)
Parameter
Symbol
Values
Min.
Typ.
Unit
Note or condition Number
Max.
Junction to case
RthJC
–
8.6
–
K/W
–
P_3.3.1
Junction to ambient
RthJA,1
–
34
–
K/W
8) 2s2p
P_3.3.2
Junction to ambient
RthJA,2
–
45
–
K/W
9) 1s0p + 600 mm²
P_3.3.3
Junction to ambient
RthJA,3
–
54
–
K/W
9) 1s0p + 300 mm²
P_3.3.4
K/W
9) 1s0p footprint
P_3.3.5
Junction to ambient
Note:
7
8
9
RthJA,4
–
116
–
This thermal data was generated in accordance with JEDEC JESD51 standards. For more information
visit www.jedec.org.
Not subject to production test, specified by design.
Specified RthJA value is according to JEDEC JESD51-2,-5,-7 at natural convection on FR4 2s2p board; the
product (chip and package) was simulated on a 76.2 × 114.3 × 1.5 mm3 board with two inner copper layers
(2 × 70 µm Cu, 2 × 35 µm Cu). Where applicable, a thermal via array next to the package contacted the first
inner copper layer.
Specified RthJA value is according to JEDEC JESD 51-3 at natural convection on FR4 1s0p board; the
product (IC and package) was simulated on a 76.2 × 114.3 × 1.5 mm3 board with 1 copper layer (1 × 70 µm
Cu).
Datasheet
10
Rev. 1.02
2021-02-05
OPTIREG™ switcher TLS4120D0EPV
2.8 MHz synchronous step down regulator
Buck regulator
4
Buck regulator
4.1
Functional description buck regulator
The TLS4120D0EPV is a synchronous current mode step down (buck) regulator with selectable switching
frequency fOSC. The device regulates the output voltage in pulse width modulation (PWM) or in pulse frequency
modulation (PFM) mode and automatically moves between both modes on load change or input voltage
change. At low input voltage conditions, for example during battery cranking, the device can operate at a duty
cycle of 100%.
4.1.1
Regulation loop and operation modes
Figure 3 shows the regulation loop. An external resistor divider is connected between VCC and AGND. The
intermediate point VFB is connected to pin FB. The error amplifier processes the difference between scaled
output feedback voltage and internal reference voltage to provide a reference current to the PWM comparator.
The PWM comparator compares that reference current to a scaled version of the inductor current to determine
the PWM duty cycle that is required for stable output voltage regulation. In PFM mode the error amplifier output
signal also serves to modulate the switching frequency.
The control logic supervises the handover between operation modes and triggers the drivers of high side PMOS
power stage and the low side NMOS power stage accordingly. For the modes of PWM, PFM and 100% duty cycle
operation see PWM (Pulse Width Modulation) mode, PFM (Pulse Frequency Modulation) mode, Continuous
conduction mode and discontinuous conduction mode and High duty cycle operation respectively.
VS
VCC
Current
sense
Internal
comp.
R1
FB
Error
amp.
R2
Softstart
GND
Control
logic
PWM
comp.
SW
LOUT
VCC
Voltage
reference
COUT
Slope
compensation
Oscillator
Clock
Clock
manager
PGND
GND
SYNC
AGND
Figure 3
Functional block diagram buck regulator
4.1.1.1
PWM (Pulse Width Modulation) mode
At high load the TLS4120D0EPV operates with the configured switching frequency fOSC in PWM mode. In PWM
mode the device modulates the duty cycle to achieve a regulated output voltage. The nominal switching
frequency can be set using one of the following methods, see Oscillator:
• by an external resistor connected at pin FREQ
• from a synchronization signal applied at the SYNC pin
The pulse width modulation is based on peak current mode detection to achieve a fast reaction time and
an optimized feedback accuracy. The PWM comparator processes the current signal detected at the high
Datasheet
11
Rev. 1.02
2021-02-05
OPTIREG™ switcher TLS4120D0EPV
2.8 MHz synchronous step down regulator
Buck regulator
side power stage as well as the current signals of the slope compensation and the error amplifier to adjust
the switching duty cycle to regulate the output voltage accordingly. With a duty cycle above 50% the slope
compensation ensures system stability. This is achieved by avoidance of subharmonic oscillations of the output
inductor current.
Due to a current sense signal inaccuracy at the beginning of each high side switch conduction phase, a short
blanking time is required to mask the output of the current sense before processing it. The blanking time
defines the minimum allowed on-time ton,min of the high side PMOS power stage and therefore the point of
transition from PWM to PFM operation.
4.1.1.2
PFM (Pulse Frequency Modulation) mode
The device can operate at constant on-time ton,min of the high side PMOS power stage to achieve a stable output
voltage at light load or high input voltage conditions. In PFM mode the device operates at a constant on-time
and modulates the switching frequency to regulate the output voltage. The switching frequency is lower than
in PWM mode. For further information about the PFM boundary condition and the frequency modulation
depending on load and on input voltage, see Typical performance characteristics buck regulator.
In PFM mode with light load the device offers optimized efficiency with reduced current consumption.
4.1.1.3
Continuous conduction mode and discontinuous conduction mode
Continuous conduction mode (CCM)
The device operates at a continuously rising or falling triangular positive inductor current. The on-time and the
switching duty cycle mainly depend on the ratio of output voltage to input voltage.
Boundary condition for CCM → DCM transition
With a decrease of the load current during continuous conduction mode, the minimum valley inductor current
can obtain approximately zero, which is the boundary condition for the discontinuous conduction mode.
Further reduction of the load current leads to discontinuous conduction mode.
Discontinuous conduction mode (DCM)
The device turns off the low side power stage to avoid a negative inductor current. Further reduction of the load
current reduces the on-time and leads to transition from PWM into PFM when obtaining the minimum on-time.
High load
PWM-CCM
IL
t
CCM-DCM
boundary
IL
t
IL
Medium-low load
PWM-DCM
t
IL
Low load
PFM-DCM
t
Figure 4
Datasheet
Typical example inductor current waveforms for CCM and DCM
12
Rev. 1.02
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OPTIREG™ switcher TLS4120D0EPV
2.8 MHz synchronous step down regulator
Buck regulator
4.1.1.4
High duty cycle operation
In 100% duty cycle mode the high side PMOS power stage constantly conducts current. If the input voltage is
close to the nominal output voltage or lower, then the device enters this operation mode, see Figure 5.
If the input voltage is decreased (for example during a battery cranking scenario) and the device moves from
regulation to the 100% duty cycle mode, then the output voltage tracks the input voltage as accurate as
possible down to an input voltage VVS of 3.7 V. During steady state operation, the difference of the output
voltage and the tracked input voltage as well as the entry point into 100% duty cycle mainly depend on the
voltage drop at the resistance Ron,hs of the high side PMOS power stage, which in turn depends on the load
current ICC. Parasitic elements of external application circuitry and components, such as the output inductor
series resistance, increase the voltage drop.
At high duty cycles close to 100%, the loop might not propagate very short off-times and compensates this by
skipping switching cycles to ensure a smooth transition to 100% duty cycle with a stable output voltage.
Commonly, regulators with adjustable output voltage are more sensitive towards noise injected into the
feedback path due to the external resistor divider. The current sense signal processing for accurate peak current
detection may reach its resolution limit at high duty cycles close to 100% due to low peak to peak inductor
currents. Therefore an optimized PCB layout and suitable external components are crucial to avoid irregular
cycles of the switching frequency and to maintain a stable output voltage.
VVS
Voltage
VCC
VCC = VCC,nom
t
Dutycycle
100%
Regulation
Tracking
Regulation
t
Figure 5
Datasheet
Typical 100% duty cycle mode tracking behavior
13
Rev. 1.02
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OPTIREG™ switcher TLS4120D0EPV
2.8 MHz synchronous step down regulator
Buck regulator
4.1.2
Power-up and power-down control
The following features of the device control power up and power down, see Table 4 for electrical characteristics:
• Startup with soft-start
• Active output discharge
4.1.2.1
Startup procedure with soft-start
The soft-start function of the TLS4120D0EPV controls the ramp-up of the output voltage with defined timing
tstart during startup, see Figure 6. If VVS > VVS,on, then a "high" signal VEN,hi at pin EN triggers the startup
procedure. During startup the internal supply establishes a stable state and the device initializes the switching
frequency and the reset function according to the configuration. The regulator then increases the output
voltage Vcc by ramping up the internal voltage reference connected to the error amplifier.
VVS
VVS > VVS,on
0V
t
VEN
VEN,hi
0V
t
VCC
Initialization
Soft-start
VCC,nom
95% of VCC,nom
5% of VCC,nom
0V
tinit
tstart
t
Figure 6
Typical startup procedure
4.1.2.2
Active output discharge
The active output discharge function of the TLS4120D0EPV controls the ramp-down of the output voltage
during power down, see Figure 7. If the device detects a "low" signal VEN,lo at the EN pin, then it switches on the
integrated discharge transistor connected to the SW pin in order to discharge the output capacitor COUT via the
output inductor LOUT. The typical on-resistance Rdc of the discharge transistor is 55 Ω.
VS
SW
Internal
supply
EN
Discharge
control
LOUT
VCC
Discharge
current
COUT
Discharge
transistor
GND
GND
Figure 7
Datasheet
Active output discharge block diagram
14
Rev. 1.02
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OPTIREG™ switcher TLS4120D0EPV
2.8 MHz synchronous step down regulator
Buck regulator
4.1.3
Protection features
The device offers features that are designed to protect it from fault events such as overcurrent, overload, input
undervoltage and overtemperature, see Table 4.
4.1.3.1
Overcurrent protection and overload protection
If the sensed current through the high side PMOS power stage exceeds the buck peak overcurrent limit IBUOC
after the blanking time of the current sense, then the device switches off the high side power stage for the
remaining time of the current cycle. Active current limitation can decrease the output voltage level.
If the sensed freewheeling current through the low side NMOS power stage exceeds the overload limit IBUOL,
then the device prevents the high side PMOS power stage from switching on in the subsequent clock cycles to
avoid overheating. The overload threshold level is set to a higher value than the overcurrent threshold level.
If an overload condition and an undervoltage condition occur for longer than 3 ms typically, then the device
detects a short circuit at the output voltage node and shuts down. After a waiting time of typically 1 s, the
device restarts with a soft-start.
4.1.3.2
Input undervoltage shutdown
The device incorporates an undervoltage shutdown function. If the input voltage VVS drops below the input
undervoltage shutdown threshold VVS,off, then the device shuts down.
4.1.3.3
Overtemperature protection
The integrated overtemperature protection turns off the device in case of a too high junction temperature. The
typical junction thermal shutdown temperature is 175°C. After the device has cooled down by the amount of the
typical junction temperature hysteresis 10 K and a subsequent waiting time of typically 1 s, the device restarts
with a soft-start to resume normal operation. The thermal shutdown is an integrated protection function to
prevent the immediate destruction of the device during fault conditions. However, a junction temperature
above 150°C is outside of the maximum ratings and reduces the lifetime of the device.
Datasheet
15
Rev. 1.02
2021-02-05
OPTIREG™ switcher TLS4120D0EPV
2.8 MHz synchronous step down regulator
Buck regulator
4.2
Electrical characteristics buck regulator
Table 4
Electrical characteristics buck regulator
VVS = 6 V to 35 V; Tj = -40°C to 150°C; all voltages with respect to ground (unless otherwise specified)
Parameter
Symbol
Values
Min.
Unit Note or condition
Number
Typ.
Max.
–
+1.5
%
6 V ≤ VVS ≤ 35 V;
PWM mode
P_4.2.1
Feedback voltage accuracy
Feedback voltage accuracy
VFB,PWM
-1.5
Feedback voltage accuracy
VFB,PFM,1 -2
–
+3.5
%
6 V ≤ VVS ≤ 35 V;
PFM mode
P_4.2.2
Feedback voltage VFB
VFB
–
0.8
–
V
–
P_4.2.5
High side MOSFET onresistance
Ron,hs
–
120
240
mΩ
ICC = 100 mA
P_4.2.7
Low side MOSFET onresistance
Ron,ls
–
70
150
mΩ
ICC = 100 mA
P_4.2.9
Maximum duty cycle
Dmax
–
–
100
%
10)
P_4.2.11
Minimum on-time,
high frequency
ton,min,hf –
78
–
ns
11) I
= 1.5 A;
valid for high frequency
operation range
P_4.2.12
Minimum on-time,
low frequency
ton,min,lf –
308
–
ns
11) I
P_4.2.13
MOSFETs
Regulation loop
CC
CC = 1.5 A;
valid for low frequency
operation range
Startup and active discharge12)
Soft-start time
tstart
0.8
1
1.2
ms
VCC rising from 5% to 95% of P_4.2.14
nominal VCC level
Startup initialization time
tinit
–
–
2.6
ms
time from rising edge of VEN
(0 V to VEN,hi ) until soft-start
P_4.2.15
Input voltage startup
threshold
VVS,on
2.6
–
6.0
V
VVS increasing;
VEN ≥ 2 V
P_4.2.16
Output discharge resistance
Rdc
–
55
–
Ω
VEN = 0 V;
VVS = 13.5 V;
VSW = 100 mV
P_4.2.17
IBUOC
2.8
3.4
4.0
A
–
P_4.2.18
Current limitation
Buck peak overcurrent limit
10
11
12
See Functional range and High duty cycle operation.
Specified by design, not subject to production test.
See Power-up and power-down control
Datasheet
16
Rev. 1.02
2021-02-05
OPTIREG™ switcher TLS4120D0EPV
2.8 MHz synchronous step down regulator
Buck regulator
Table 4
Electrical characteristics buck regulator (continued)
VVS = 6 V to 35 V; Tj = -40°C to 150°C; all voltages with respect to ground (unless otherwise specified)
Parameter
Symbol
Values
Min.
3.4
Unit Note or condition
Number
Typ.
Max.
3.9
4.4
A
–
P_4.2.20
Overload current limit
IBUOL
Overload overcurrent gap
IBUOL,gap 0.05
0.5
–
A
Overload current limit is
typically 0.5 A above buck
peak overcurrent limit
P_4.2.22
Input undervoltage shutdown
threshold
VVS,off
3.3
–
3.55
V
VVS decreasing
P_4.2.23
Input undervoltage shutdown
hysteresis
VVS,hys
180
280
420
mV
–
P_4.2.24
Undervoltage shutdown
Datasheet
17
Rev. 1.02
2021-02-05
OPTIREG™ switcher TLS4120D0EPV
2.8 MHz synchronous step down regulator
Buck regulator
4.3
Typical performance characteristics buck regulator
FREQ: 2.2 MHz; VVS = 13.5 V; Tj = 25°C (if not otherwise specified). The shown performance characteristics was
measured on a 4 layer FR4 printed circuit board with external components as recommended in Application
information.
Efficiency
FREQ: 440 kHz; Tj = 25°C; VCC = 5 V
Efficiency
FREQ: 440 kHz; Tj = 25°C; VCC = 5 V
Efficiency
FREQ: 2.2 MHz; Tj = 25°C; VCC = 5 V
Efficiency
FREQ: 2.2 MHz; Tj = 25°C; VCC = 5 V
Datasheet
18
Rev. 1.02
2021-02-05
OPTIREG™ switcher TLS4120D0EPV
2.8 MHz synchronous step down regulator
Buck regulator
Efficiency
FREQ: 440 kHz; Tj = 25°C; VCC = 3.3 V
Efficiency
FREQ: 440 kHz; Tj = 25°C; VCC = 3.3 V
Efficiency
FREQ: 2.2 MHz; Tj = 25°C; VCC = 3.3 V
Efficiency
FREQ: 2.2 MHz; Tj = 25°C; VCC = 3.3 V
Datasheet
19
Rev. 1.02
2021-02-05
OPTIREG™ switcher TLS4120D0EPV
2.8 MHz synchronous step down regulator
Buck regulator
Line regulation
ICC = 1 A; VCC = 5 V
Load regulation
VVS = 13.5 V; VCC = 5 V
Line regulation
ICC = 1 A; VCC = 3.3 V
Load regulation
VVS = 13.5 V; VCC = 3.3 V
Datasheet
20
Rev. 1.02
2021-02-05
OPTIREG™ switcher TLS4120D0EPV
2.8 MHz synchronous step down regulator
Buck regulator
Output voltage precision
ICC = 200 mA; VCC = 5 V
Output voltage precision
ICC = 200 mA; VCC = 3.3 V
Line regulation (low load)
ICC = 100 µA; VCC = 5 V
Line regulation (low load)
ICC = 100 µA; VCC = 3.3 V
Datasheet
21
Rev. 1.02
2021-02-05
OPTIREG™ switcher TLS4120D0EPV
2.8 MHz synchronous step down regulator
Buck regulator
High side MOSFET on-resistance
ICC = 100 mA
Low side MOSFET on-resistance
ICC = 100 mA
Output discharge resistance
VEN = 0 V; VSW = 100 mV
Input undervoltage shutdown threshold
VVS decreasing
Datasheet
22
Rev. 1.02
2021-02-05
OPTIREG™ switcher TLS4120D0EPV
2.8 MHz synchronous step down regulator
Buck regulator
PFM frequency modulation (CCM)
FREQ: 440 kHz; ICC = 1.5 A; VCC = 5 V
PFM frequency modulation (CCM)
FREQ: 2.2 MHz; ICC = 1.5 A; VCC = 5 V
PFM frequency modulation (DCM)
FREQ: 440 kHz; Tj = 25°C; VCC = 5 V
PFM frequency modulation (DCM)
FREQ: 2.2 MHz; Tj = 25°C; VCC = 5 V
Datasheet
23
Rev. 1.02
2021-02-05
OPTIREG™ switcher TLS4120D0EPV
2.8 MHz synchronous step down regulator
Buck regulator
PFM frequency modulation (CCM)
FREQ: 440 kHz; ICC = 1.5 A; VCC = 3.3 V
PFM frequency modulation (CCM)
FREQ: 2.2 MHz; ICC = 1.5 A; VCC = 3.3 V
PFM frequency modulation (DCM)
FREQ: 440 kHz; Tj = 25°C; VCC = 3.3 V
PFM frequency modulation (DCM)
FREQ: 2.2 MHz; Tj = 25°C; VCC = 3.3 V
Datasheet
24
Rev. 1.02
2021-02-05
OPTIREG™ switcher TLS4120D0EPV
2.8 MHz synchronous step down regulator
Buck regulator
PFM boundary
Tj = 25°C; VCC = 3.3 V
PFM boundary
Tj = 25°C; VCC = 5 V
Buck peak overcurrent limit
VVS = 13.5 V
Overload current limit
VVS = 13.5 V
Datasheet
25
Rev. 1.02
2021-02-05
OPTIREG™ switcher TLS4120D0EPV
2.8 MHz synchronous step down regulator
Buck regulator
Load step response
ICC: 0.6 A to 2 A to 0.6 A; VCC = 5 V
Load step response
ICC: 0.6 A to 2 A to 0.6 A; VCC = 3.3 V
V CC [100 mV/div]
V CC [100 mV/div]
I CC [2 A/div]
I CC [2 A/div]
3.3 V
5V
0.6 A
0.6 A
-0.5
0
0.5
1
-0.5
1.5
0.5
1
1.5
t [ms]
t [ms]
Datasheet
0
26
Rev. 1.02
2021-02-05
OPTIREG™ switcher TLS4120D0EPV
2.8 MHz synchronous step down regulator
Oscillator
5
Oscillator
5.1
Functional description oscillator
The integrated clock provides a constant frequency to the regulation loop. In PWM mode the device switches on
and off the high side and low side power stages at the oscillator frequency fOSC.
The oscillator frequency can be set by connecting a resistor RFREQ between the FREQ pin and ground, see Table
5, Table 6 and Table 7. The device sets the selected switching frequency during startup.
Table 5
FREQ configuration for typical oscillator frequencies in the low frequency range
RFREQ [kΩ]13)
fOSC [kHz]
2.2
320
3.3
360
4.7
400
≤ 1.0 (or connect FREQ pin directly to GND)
44014)
6.8
480
10
520
15
560
Table 6
FREQ configuration for typical oscillator frequencies in the high frequency range
RFREQ [kΩ]15)
fOSC [MHz]
22
1.6
33
1.8
47
2.0
≥ 200 (or leave FREQ pin open)
2.216)
68
2.4
100
2.6
150
2.8
5.1.1
Synchronization input
In PWM mode the device can synchronize the switching frequency to an external oscillator connected to the
SYNC pin. The internal clock manager triggers at the falling edge of the external signal. The phase shift towards
the switching frequency can be adjusted with the duty cycle of the external oscillator. 50% duty cycle of the
external oscillator corresponds to a phase shift of approximately zero. A suitable setting of RFREQ is required
so that the internal operation frequency is equal to the corresponding external synchronization frequency or
above it. This is a prerequisite for the automatic transitions between PWM mode and PFM mode.
As soon as the startup is completed and the device accepts the external signal at the SYNC pin, the
synchronization turns active.
13
14
15
16
Resistor tolerance ≤ 5%.
Default oscillator low frequency.
Resistor tolerance ≤ 5%.
Default oscillator high frequency.
Datasheet
27
Rev. 1.02
2021-02-05
OPTIREG™ switcher TLS4120D0EPV
2.8 MHz synchronous step down regulator
Oscillator
5.1.2
Spread spectrum
In PWM mode, when used without an external clock at the SYNC pin, the TLS4120D0EPV can apply spread
spectrum to optimize EMI performance. The device modulates the switching frequency up and down by a
triangle waveform with a typical frequency of 8.3 kHz within a range of typically ±7.5% of the selected oscillator
frequency. The logical signal on the SSON pin switches spread spectrum on or off.
5.2
Electrical characteristics oscillator
Table 7
Electrical characteristics oscillator
VVS = 6 V to 35 V; Tj = -40°C to 150°C; all voltages with respect to ground (unless otherwise specified)
Parameter
Symbol
Values
Min.
Typ.
Unit
Note or condition Number
Max.
Frequency setting
Default oscillator low frequency
fosc,1
396
440
484
kHz
RFREQ ≤ 1.0 kΩ or
connect FREQ pin
directly to GND
P_5.2.1
Default oscillator high frequency
fosc,2
1.98
2.2
2.42
MHz
RFREQ ≥ 200 kΩ or
leave FREQ pin
open
P_5.2.2
Oscillator frequency
fosc,3
288
320
352
kHz
RFREQ = 2.2 kΩ
P_5.2.3
Oscillator frequency
fosc,4
324
360
396
kHz
RFREQ = 3.3 kΩ
P_5.2.4
Oscillator frequency
fosc,5
360
400
440
kHz
RFREQ = 4.7 kΩ
P_5.2.5
Oscillator frequency
fosc,6
432
480
528
kHz
RFREQ = 6.8 kΩ
P_5.2.6
Oscillator frequency
fosc,7
468
520
572
kHz
RFREQ = 10 kΩ
P_5.2.7
Oscillator frequency
fosc,8
504
560
616
kHz
RFREQ = 15 kΩ
P_5.2.8
Oscillator frequency
fosc,9
1.44
1.6
1.76
MHz
RFREQ = 22 kΩ
P_5.2.9
Oscillator frequency
fosc,10
1.62
1.8
1.98
MHz
RFREQ = 33 kΩ
P_5.2.10
Oscillator frequency
fosc,11
1.8
2.0
2.2
MHz
RFREQ = 47 kΩ
P_5.2.11
Oscillator frequency
fosc,12
2.16
2.4
2.64
MHz
RFREQ = 68 kΩ
P_5.2.12
Oscillator frequency
fosc,13
2.34
2.6
2.86
MHz
RFREQ = 100 kΩ
P_5.2.13
Oscillator frequency
fosc,14
2.52
2.8
3.08
MHz
RFREQ = 150 kΩ
P_5.2.14
Synchronization low frequency
capture range
fsync,lf
320
–
560
kHz
17) valid for
P_5.2.15
Synchronization high frequency
capture range
fsync,hf
1.6
–
2.8
MHz
17) valid for
P_5.2.16
SYNC "high" signal
VSYNC,hi
3.0
–
–
V
Synchronization input
17
oscillator low
frequency range
oscillator high
frequency range
17) 5.5V ≤ V
VS
≤ 35 V P_5.2.17
Synchronization of PWM to the falling edge.
Datasheet
28
Rev. 1.02
2021-02-05
OPTIREG™ switcher TLS4120D0EPV
2.8 MHz synchronous step down regulator
Oscillator
Table 7
Electrical characteristics oscillator (continued)
VVS = 6 V to 35 V; Tj = -40°C to 150°C; all voltages with respect to ground (unless otherwise specified)
Parameter
Symbol
Values
Min.
Typ.
Unit
Note or condition Number
Max.
SYNC "low" signal
VSYNC,lo
–
–
0.8
V
17)
P_5.2.21
SYNC signal hysteresis
VSYNC,hys
45
255
600
mV
17)
P_5.2.22
SYNC "high" input current
ISYNC,hi
–
0.1
1
µA
VSYNC = 5 V
P_5.2.25
SYNC "low" input current
ISYNC,lo
–
0.1
1
µA
VSYNC = 0 V
P_5.2.26
SYNC signal duty cycle
DSYNC
10
–
90
%
–
P_5.2.28
Spread spectrum "high" signal
VSSON,hi
2.0
–
–
V
Enables spread
spectrum
P_5.2.29
Spread spectrum "low" signal
VSSON,lo
–
–
0.8
V
Disables spread
spectrum
P_5.2.30
Spread spectrum enable hysteresis VSSON,hys
100
250
1000
mV
–
P_5.2.31
Spread spectrum enable "high"
input current
ISSON,hi
0.7
1
1.25
µA
VSSON = 5.0 V
P_5.2.32
Spread spectrum modulation
frequency
fSS,mod
7.5
8.3
9.3
kHz
Spread spectrum
enabled
P_5.2.33
Spread spectrum modulation
range
fSS,range
–
±7.5
–
%
Spread spectrum
enabled
P_5.2.34
Spread spectrum
17
Synchronization of PWM to the falling edge.
Datasheet
29
Rev. 1.02
2021-02-05
OPTIREG™ switcher TLS4120D0EPV
2.8 MHz synchronous step down regulator
Oscillator
5.3
Typical performance characteristics oscillator
Oscillator (low frequency)
VVS = 13.5 V; FREQ: 440 kHz
Datasheet
Oscillator (high frequency)
VVS = 13.5 V; FREQ: 2.2 MHz
30
Rev. 1.02
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OPTIREG™ switcher TLS4120D0EPV
2.8 MHz synchronous step down regulator
Current consumption and enable
6
Current consumption and enable
6.1
Functional description current consumption and enable
A "high" signal VEN,hi at the EN pin switches on the regulator. In on-state the device can operate at very low
current consumption IVS,on to improve the efficiency with low load in PFM mode.
A "low" signal VEN,lo at the EN pin switches the regulator off. In turned off-state, the current consumption IVS,off
of the device is 1 µA typically. If the EN pin is left open, then an internal pull-down resistor REN,int ensures that
the device remains switched off.
6.2
Electrical characteristics current consumption and enable
Table 8
Electrical characteristics current consumption and enable
VVS = 6 V to 35 V; Tj = -40°C to 150°C; all voltages with respect to ground (unless otherwise specified)
Parameter
Symbol
Values
Min.
Typ.
Unit
Note or condition
Number
Max.
Current consumption
Current consumption in off- IVS,off
state
–
1
2
µA
VEN = 0 V;
VVS = 13.5 V;
Tj < 85°C
P_6.2.1
Current consumption in on- IVS,on
state
–
31
65
µA
VEN = 5.0 V;
VVS = 13.5 V;
Tj < 85°C;
not switching18)
P_6.2.2
Enable
Enable "high" signal
VEN,hi
2.0
–
–
V
–
P_6.2.3
Enable "low" signal
VEN,lo
–
–
0.8
V
–
P_6.2.4
Enable hysteresis
VEN,hys
100
400
1000
mV
–
P_6.2.5
Enable "high" input current IEN,hi,1
–
0.6
1
µA
VEN = 5.0 V
P_6.2.6
Enable "high" input current IEN,hi,2
–
2.5
3.5
µA
VEN = 13.5 V
P_6.2.7
Enable, internal resistor to
GND
5.6
8
10.4
MΩ
VEN = 2.0 V
P_6.2.8
18
REN,int
The current consumption is tested while the output voltage is forced to a slightly higher value than the
nominal output voltage to prevent switching activities of the regulator.
Datasheet
31
Rev. 1.02
2021-02-05
OPTIREG™ switcher TLS4120D0EPV
2.8 MHz synchronous step down regulator
Current consumption and enable
6.3
Typical performance characteristics current consumption and
enable
Current consumption in off-state
VVS = 13.5 V; VEN = 0 V
Current consumption in on-state
VVS = 13.5 V; VEN = 5 V; no switching
Enable "high" input current
VVS = 13.5 V
Datasheet
32
Rev. 1.02
2021-02-05
OPTIREG™ switcher TLS4120D0EPV
2.8 MHz synchronous step down regulator
Reset
7
Reset
7.1
Functional description reset
The reset function supervises the regulator output voltage VCC by monitoring the feedback voltage VFB. The
device indicates the reset status at the RO pin. RO "high" indicates, that the output voltage is within the desired
reset thresholds. RO "low" indicates that the output voltage is outside the desired reset thresholds. As long as
the device operates within the specified range, the reset function is active, see Table 10 and Functional range.
Reset output RO
The reset output pin RO is an open drain structure and needs to be pulled up to VCC or to a voltage rail via an
external pull-up resistor RRO, which must be chosen according to the maximum pull-up current IRO,lo. During
battery cranking conditions of the input voltage VVS, the reset feature is active down to an input voltage VVS of
2.8 V.
Power-on reset delay time
Power-on reset delay time tRD,PWR-on is the time period from completion of the soft-start until the device
releases the reset by switching the reset output RO from "low" to "high", see Figure 8. An external resistor RRT
connected to the RT pin determines the value of power-on reset delay time tRD,PWR-on, see Table 9.
Reset undervoltage, overvoltage and delay time
In contrast to the power-on reset delay time tRD,PWR-on, the reset delay time tRD refers to an output undervoltage
or output overvoltage event during operation, see Figure 8. If VFB drops below the undervoltage reset threshold
VRT,UV,th, then the device sets the reset signal at the RO to "low". When the output voltage recovers and VFB
exceeds the undervoltage reset threshold plus the hysteresis (VRT,UV,th + VRT,UV,hys), then the device sets the
RO pin to "high" after the reset delay time tRD. In accordance with the undervoltage reset delay time, the
overvoltage reset delay time tRD considers an output overvoltage event. If case VFB exceeds the overvoltage
reset threshold VRT,OV,th, then the device sets the RO pin to "low". When the output voltage recovers and VFB
drops below the overvoltage reset threshold minus the hysteresis (VRT,OV,th - VRT,OV,hys), then the device sets the
RO pin to "high" after the reset delay time tRD. An external resistor RRT connected to the RT pin determines the
value of the reset delay time tRD along with the reset undervoltage threshold VRT,UV,th, see Table 9. The device
sets the selected reset delay time and reset threshold during initialization phase. The value of the overvoltage
reset threshold VRT,OV,th is fixed.
Reset reaction time
If the output voltage of the regulator drops below the output undervoltage reset threshold VRT,UV,th or rises
above the output overvoltage reset threshold VRT,OV,th, then this triggers the internal output voltage monitoring
circuit. If that condition lasts longer than the blanking time tr,blank (see Table 10), then the device sets the reset
signal at the RO pin to "low". If the output overvoltage or undervoltage condition lasts shorter than tr,blank, then
the device keeps the reset signal "high". This prevents a microcontroller reset due to very short distortions of
the output voltage, see Figure 8.
Datasheet
33
Rev. 1.02
2021-02-05
OPTIREG™ switcher TLS4120D0EPV
2.8 MHz synchronous step down regulator
Reset
Table 9
RT configuration for typical values of power-on, undervoltage, overvoltage reset delay
time and undervoltage reset threshold
RRT [kΩ]19)
tRD,PWR-on [ms]
tRD [ms]
VRT,UV,th [% of VFB]20)
≤ 1.0 (or connect to GND)
0.06
0.03
-8
2.2
0.06
0.03
-14
3.3
0.06
0.03
-25
4.7
0.06
0.03
-40
6.8
1.9
1.3
-8
10
1.9
1.3
-14
15
1.9
1.3
-25
22
1.9
1.3
-40
33
7.7
5.1
-14
47
7.7
5.1
-25
68
7.7
5.1
-40
100
15.4
10.2
-8
150
15.4
10.2
-14
≥ 200 (or leave open)
7.7
5.1
-8
VEN
VEN,hi
VEN,lo
VCC
Softstart
Undervoltage
Short undervoltage
Undervoltage
t
Overvoltage
t < tr,blank
VRT,OV,th
VRT,UV,th
t
VRO
tRD,PWR-on
tr,blank
tRD
tr,blank
tRD
tr,blank
tRD
VPU
VRO,lo
t
Figure 8
19
20
21
Reset timing diagram21)
Resistor tolerance ≤ 5%.
In relation to the typical feedback voltage level 0.8 V.
The diagram neglects the reset undervoltage hysteresis and reset overvoltage hysteresis to improve the
overview. VRO is connected to an external pull-up voltage VPU via an external pull-up resistor. The input
voltage VVS is set to a level higher than VVS,on.
Datasheet
34
Rev. 1.02
2021-02-05
OPTIREG™ switcher TLS4120D0EPV
2.8 MHz synchronous step down regulator
Reset
7.2
Electrical characteristics reset
Table 10
Electrical characteristics reset
VVS = 6 V to 35 V; Tj = -40°C to 150°C; all voltages with respect to ground (unless otherwise specified)
Parameter
Symbol
Values
Min.
Typ.
Unit
Note or condition
Number
Max.
Reset output RO
Reset output "low" voltage
VRO,lo
–
–
0.4
V
VEN ≥ 2 V;
IRO ≤ 1.5 mA
P_7.2.1
Reset output "low" pull-up
current
IRO,lo
–
–
1.5
mA
VEN ≥ 2 V;
VRO = 0.4 V
P_7.2.2
Reset output "high"
leakage current
IRO,hi
–
–
1
µA
VRO = 5 V
P_7.2.3
Output overvoltage reset threshold
Output overvoltage reset
threshold increasing
VRT,OV,th
5
7
9
%
percentage of VFB
P_7.2.4
Output overvoltage reset
hysteresis
VRT,OV,hys
–
1
2
%
percentage of VFB
P_7.2.5
Output undervoltage reset threshold22)
Output undervoltage reset
threshold decreasing -8%
VRT,UV,th,1
-10
-8
-6
%
percentage of VFB
P_7.2.6
Output undervoltage reset
threshold decreasing -14%
VRT,UV,th,2
-16
-14
-12
%
percentage of VFB
P_7.2.7
Output undervoltage reset
threshold decreasing -25%
VRT,UV,th,3
-27
-25
-23
%
percentage of VFB
P_7.2.8
Output undervoltage reset
threshold decreasing -40%
VRT,UV,th,4
-42
-40
-38
%
percentage of VFB
P_7.2.9
Output undervoltage reset
hysteresis
VRT,UV,hys
–
1
2
%
percentage of VFB
P_7.2.10
Reset delay timing22)
Power-on reset delay time
60 µs
tRD,PWR-on,1 15
60
90
µs
–
P_7.2.11
Power-on reset delay time
1.9 ms
tRD,PWR-on,2 1.7
1.9
2.2
ms
–
P_7.2.12
Power-on reset delay time
7.7 ms
tRD,PWR-on,3 6.9
7.7
8.6
ms
–
P_7.2.13
Power-on reset delay time
15.4 ms
tRD,PWR-on,4 13.9
15.4
17.1
ms
–
P_7.2.14
Reset delay time 30 µs
tRD,1
30
95
µs
–
P_7.2.15
22
15
For RT configuration see Table 9
Datasheet
35
Rev. 1.02
2021-02-05
OPTIREG™ switcher TLS4120D0EPV
2.8 MHz synchronous step down regulator
Reset
Table 10
Electrical characteristics reset (continued)
VVS = 6 V to 35 V; Tj = -40°C to 150°C; all voltages with respect to ground (unless otherwise specified)
Parameter
Symbol
Values
Min.
Typ.
Unit
Note or condition
Number
Max.
Reset delay time 1.3 ms
tRD,2
1.1
1.3
1.5
ms
–
P_7.2.16
Reset delay time 5.1 ms
tRD,3
4.6
5.1
5.7
ms
–
P_7.2.17
Reset delay time 10.2 ms
tRD,4
9.3
10.2
11.4
ms
–
P_7.2.18
Reset blanking time
tr,blank
2
5
10
µs
–
P_7.2.19
Datasheet
36
Rev. 1.02
2021-02-05
OPTIREG™ switcher TLS4120D0EPV
2.8 MHz synchronous step down regulator
Reset
7.3
Typical performance characteristics reset
Output undervoltage reset threshold
VVS = 13.5 V
Datasheet
Output overvoltage reset threshold
VVS = 13.5 V
37
Rev. 1.02
2021-02-05
OPTIREG™ switcher TLS4120D0EPV
2.8 MHz synchronous step down regulator
Application information
8
Application information
Note:
The following information is given as an example for the implementation of the device only and shall
not be regarded as a description or warranty of a certain functionality, condition or quality of the
device.
DIN *)
LIN **)
VBAT
CIN3 **)
CIN2
CIN1
VS
Enable signal (e.g. from IGN)
VS
EN
RFREQ *)
Enable
UVLO
Over
temperature
shutdown
Bandgap
reference
Internal
supply
FREQ
Control loop
+ driver
Synchronisation signal (e.g. from µC)
SYNC
SW
SSON
ON/OFF control for
spread spectrum
VCC
CFF
Oscillator
PGND
High signal
(e.g. VCC)
LOUT
Spread
spectrum
R1
R2
COUT
FB
VPU
Soft-start
ramp
generator
RRO
RT
Reset
RRT *)
pull-up voltage
RO
Reset signal
(e.g. indicate output voltage status to µC)
AGND
*) optional
**) optional for improved EMI performance
Figure 9
Note:
Datasheet
Application diagram
This figure is a simplified example of an application circuit. The function must be verified in the
application.
38
Rev. 1.02
2021-02-05
OPTIREG™ switcher TLS4120D0EPV
2.8 MHz synchronous step down regulator
Application information
Table 11
Recommended values for components in the application diagram
Name
Value23)
Switching
frequency range
Output voltage
range
Component type
CIN1
100 nF
–
–
Ceramic X7R capacitor; 50 V
CIN2
10 µF
–
–
Ceramic X7R capacitor; 50 V
LOUT
22 µH
320 kHz to
560 kHz
–
Shielded power inductor; ISAT > IBUOC
DCR < 70 mΩ
COUT
88 µF24)
320 kHz to
560 kHz
–
22 µF (x4) ceramic X7R capacitor; 16 V
LOUT
2.2 µH
1.6 MHz to
2.8 MHz
3 V ≤ VCC ≤ 5 V
Shielded power inductor; ISAT > IBUOC
DCR < 70 mΩ
COUT
44 µF24)
1.6 MHz to
2.8 MHz
3 V ≤ VCC ≤ 5 V
22 µF (x2) ceramic X7R capacitor; 16 V
LOUT
4.7 µH
1.6 MHz to
2.8 MHz
5 V < VCC ≤ 10 V
Shielded power inductor; ISAT > IBUOC
DCR < 70 mΩ
COUT
22 µF24)
1.6 MHz to
2.8 MHz
5 V < VCC ≤ 10 V
22 µF ceramic X7R capacitor; 25 V
8.1
Output voltage adjustment
The output voltage of the TLS4120D0EPV can be adjusted with an external voltage divider connected to the FB
pin. To achieve a high output voltage accuracy, a resistor R2 < 160 kΩ is recommended. By neglecting the current
flowing into the FB pin, the desired resistance R1 can be calculated depending on the required nominal output
voltage VCC:
R1 = R2
V CC
V FB
−1
Equation 1
8.2
Feedforward capacitor
An additional feedforward capacitor CFF between the output voltage node VCC and the feedback pin FB might be
required for stable operation (see Figure 9). A good starting value is a feedforward capacitor of 10 pF, but the
best value may be higher due to additional parasitic capacitance at the FB pin to GND resulting from the PCB
layout. The capacitance must match the conditions of the application.
23
24
Typical condition
For maintenance of loop stability it is recommended to use capacitors with a limited voltage derating at
the typical output voltage level. A capacitor in parallel can be added to match the recommended typical
capacitance value as close as possible.
Datasheet
39
Rev. 1.02
2021-02-05
OPTIREG™ switcher TLS4120D0EPV
2.8 MHz synchronous step down regulator
Application information
8.3
Layout recommendations
Introduction
A switch mode power supply is a potential source of electromagnetic disturbance, which may affect the
application environment as well as the device itself. This can lead to sporadic malfunction including regulator
instability or irreversible damage depending on the amount of generated disturbance.
Main types of electromagnetic disturbance:
•
Radiated emission
•
Conducted emission
Radiated emission
Radiated emission is caused by circulating currents and voltage oscillations. Alternating currents appear in so
called current windows, which are defined by the area of the circulating current within the corresponding filter
stage at the input or the output of the regulator. Voltage oscillations are mainly caused by resonant circuits
induced by parasitic inductance and capacitance of the PCB layout.
The following PCB layout design recommendations help to minimize radiated emission:
•
Place external components close to the device to reduce parasitic elements of the PCB layout and to
keep the area of circulating currents small. At the same time some distance should be kept between the
components to avoid coupling.
• Reduce the switching area at pin SW to minimize the inductance and especially the parasitic capacitance.
The parasitic capacitance can be further reduced by removing inner GND layers below the switching area.
Routing of other signal traces below the switching area should be avoided generally.
•
Use GND layers to shield areas with alternating currents or voltage oscillations.
Conducted emission
Conducted emission consists of voltage oscillations, which occur permanently or by occasion at the regulator
input or output connection. Their frequency range can exceed 100 MHz and they are superimposed to the input
voltage VVS and to the output voltage VCC. This might disturb other components of the application.
Countermeasures against conducted disturbances are the same as against radiated emission. The following
recommendations can further reduce the conducted emission:
•
Reduce high frequency conducted emission by placing well connected small ceramic filter capacitors (1 nF
to 220 nF) with low ESR and low ESL in parallel to the input capacitors as close as possible to the input pin
VS and in parallel to the output capacitor COUT close to the output inductor LOUT.
•
Reduce noise injected into the battery supply line by using a π-filter, for example consisting of CIN1, CIN2,
CIN3 and LIN. This requires additional capacitors and an inductor. The filter must be designed according to
the requirements of the application.
8.4
Additional information
Please contact Infineon:
•
for information regarding the pin behavioral assessment
•
for application notes with more detailed information about this device
•
for any further information visit https://www.infineon.com/
Datasheet
40
Rev. 1.02
2021-02-05
OPTIREG™ switcher TLS4120D0EPV
2.8 MHz synchronous step down regulator
Package information
2)
0.25±0.05
0.25
0.1 2x
0.67±0.25
0.08 C
Coplanarity
6±0.2
A-B C 14x
0.2 D 14x
Bottom View
A
Index
Marking
14
8
8
14
1
7
7
1
B
0°...8°
C
Seating
Plane
1)
3.9±0.1
0.65
4±0.1
2.65±0.1
0.1 2x
1.15 Max.
1)
4.9±0.1
(0.2)
0.05±0.05
Standoff
Package information
(0.95)
9
0.15
0.15
D
A-B
1) Does not include plastic or metal protrusion of 0.15 max. per side
2) Dambar protrusion shall be maximum 0.1 mm total in excess of lead width.
All dimensions are in units mm
The drawing is in compliance with ISO 128-30, Projection Method 1 [
]
Figure 10
PG-TSDSO-14
Green Product (RoHS compliant)
To meet the world-wide customer requirements for environmentally friendly products and to be compliant with
government regulations the device is available as a Green Product. Green Products are RoHS compliant (Pb-free
finish on leads and suitable for Pb-free soldering according to IPC/JEDEC J-STD-020).
Information on alternative packages
Please visit www.infineon.com/packages.
Datasheet
41
Rev. 1.02
2021-02-05
OPTIREG™ switcher TLS4120D0EPV
2.8 MHz synchronous step down regulator
Revision history
Revision history
Version
Date
Changes
Rev. 1.02 2021-02-05 Editorial changes
Rev. 1.01 2020-10-15 Editorial changes
Rev. 1.0
Datasheet
2020-03-20 Initial datasheet
42
Rev. 1.02
2021-02-05
Trademarks
All referenced product or service names and trademarks are the property of their respective owners.
Edition 2021-02-05
Published by
Infineon Technologies AG
81726 Munich, Germany
© 2021 Infineon Technologies AG
All Rights Reserved.
Do you have a question about any
aspect of this document?
Email: erratum@infineon.com
Document reference
IFX-Z8F63766653
IMPORTANT NOTICE
The information given in this document shall in no
event be regarded as a guarantee of conditions or
characteristics (“Beschaffenheitsgarantie”).
With respect to any examples, hints or any typical
values stated herein and/or any information regarding
the application of the product, Infineon Technologies
hereby disclaims any and all warranties and liabilities
of any kind, including without limitation warranties of
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In addition, any information given in this document is
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customer’s products and any use of the product of
Infineon Technologies in customer’s applications.
The data contained in this document is exclusively
intended for technically trained staff. It is the
responsibility of customer’s technical departments to
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information given in this document with respect to such
application.
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