TLE6389G50 [INFINEON]
Step - Down DC/DC Controller; 步骤 - 降压型DC / DC控制器
| 型号： | TLE6389G50 |
| 厂家： | 
Infineon |
| 描述： | Step - Down DC/DC Controller |
| 文件： | 总24页 (文件大小：130K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
Step-Down DC/DC Controller
Target Datasheet
TLE 6389
Features
• Operation from 5V to 60V Input Voltage
• 100% Maximum Duty Cycle
• Efficiency >90%
• Output Current up to 3A
P-DSO-14-3, -4, -9, -11
• Less than 100µA Quiescent Current
• 2µA Max Shutdown Current
• Up to 350kHz Switching Frequency
RSENSE
=
• Adjustable and Fixed 5V and
M1
L1 = 47 µH
VIN
VOUT
IOUT
0.05
3.3V Output Voltage versions
• 3% output voltage accuracy
(PWM Mode)
• Current-Mode Control Scheme
• On Chip Low Battery Detector
• Ambient operation range
-40°C to 125°C
CIN1
100
=
COUT
100
=
F
CBDS
=
µF
D1
µ
220 nF
M1: Infineon SPD09P06PL
D1: Motorola MBRD360
L1: Coilcraft DO3340P-473
Cin1: TBD
11
BDS
14
12
GDRV
2
CS
3
FB
13
7
VOUT
VS
RSI1
=
CIN2
=
9
SO
Cout: Low ESR Tantalum
400k
220nF
TLE6389G50-1
10
SI
RO
RD
RSI2=
SI_GND SI_ENABLE SYNC GND
100k
6
1
5
4
8
CRD =100nF
ON OFF
Type
Ordering Code
on request
on request
on request
on request
on request
Package
Description
adjustable
TLE 6389 GV
TLE 6389 G50
TLE 6389 G50-1
TLE 6389 G33
TLE 6389 G33-1
P-DSO-14
P-DSO-14
P-DSO-14
P-DSO-14
P-DSO-14
5V, Device Enable
5V, SI GND, SI Enable
3.3V, Device Enable
3.3V, SI GND, SI Enable
Functional description
The TLE6389 step-down DC-DC switching controllers provide high efficiency over loads
ranging from 1mA up to 3A. A unique PWM/PFM control scheme operates with up to a
100% duty cycle, resulting in very low dropout voltage. This control scheme eliminates
minimum load requirements and reduces the supply current under light loads to 100µA.
These step-down controllers drive an external P-channel MOSFET, allowing design
flexibility for applications up to 3A. A high switching frequency (up to 350kHz) and
Target Datasheet Rev. 1.7
1
2001-09-17
TLE 6389
operation in continuous-conduction mode allow the use of tiny surface-mount inductors.
Output capacitor requirements are also reduced, minimizing PC board area and system
costs. The output voltage is preset at 5V (TLE6389-50) or 3.3V (TLE6389-33) and
adjustable for the TLE6389. Input voltages can be up to 60V.
Pin Configuration (top view)
ENABLE /
1
2
3
4
5
6
7
14 CS
SI_EN
FB
13 VS
VOUT
GND
12 GDRV
11 BDS
10 RO
P-D-SO-14
SYNC
SI_GND
SI
9
8
SO
RD
Pin Definitions and Functions
Pin No
SO-14
Symbol Function
2
FB
Feedback Input.
1. For adjustable-output operation connect to an external voltage divider
between the output and GND (see the Setting the Output Voltage section).
2. Sense input for fixed 5V or 3.3V output operation. FB is internally
connected to an on-chip voltage divider.
3
1
VOUT
VOUT Input.
Input for internal supply. Connect to output if variable version is used. For
fixed voltage version connect FB and VOUT.
ENABLE Active-Low Enable Input. Device is placed in shutdown when Enable is
driven low. In shutdown mode, the reference, output, and external
MOSFET are turned off. Connect to logic high for normal operation.
(TLE6389G50, TLE6389G33, TLE6389GV only)
Target Datasheet Rev. 1.7
2
2001-09-17
TLE 6389
Pin No
SO-14
Symbol Function
SI_ENA SI Enable Input. SI_GND is switched to high impedance when SI_Enable
1
BLE
is low. High level at SI_Enable connects SI_GND to GND via a low
impedance path. SO is undefined when SI_Enable is low. (TLE6389G50-
1, TLE6389G33-1 only)
13
4
VS
Supply Input. Bypass with 0.47µF.
Ground. Analog signal ground.
GND
6
SI_GND SI Ground. Ground connection for SI comparator resistor devider.
11
BDS
Buck Driver Supply Input. Connect ceramic capacitor between BDS and
VS to generate clamped gate-source voltage to drive the PMOS power
stage.
14
CS
Current-Sense Input. Connect current-sense resistor between VS and
CS. External MOSFET is turned off when the voltage across the resistor
equals the current-limit trip level.
12
10
GDRV
RO
Gate Drive Output for External P-Channel MOSFET. GDRV swings
between VS and BDS.
Reset Output. Open drain output from reset comparator with an internal
pull up resistor.
8
9
RD
SO
Reset Delay. Connect a capacitor to ground for delay time adjustment.
Sense Output Comparator. Open drain output from SI comparator with
an internal pull up resistor.
7
5
SI
Sense Input Comparator. Input to the Low-Battery Comparator. This
input is compared to an internal 1.25V reference.
SYNC
Input for external synchronization. An external clock signal connected
to this pin allows for GDRV switching synchronization.
Target Datasheet Rev. 1.7
3
2001-09-17
TLE 6389
1
Absolute Maximum Ratings
Item
Parameter
Symbol Limit Values Unit Remarks
min.
max.
Supply Input
Voltage
1.0.1
1.0.2
VS
IS
-0.3
–
60
–
–
V
–
Current
Current Sense Input
Voltage
1.0.3
1.0.4
VCS
ICS
-0.3
–
60
–
–
V
–
Current
Gate Drive Output
Voltage
1.0.5
1.0.6
VGDRV
– 0.3
6.8
V
|VS –
VGDRV|<6.8V
Current
IGDRV
–
–
Internally limited
–
Buck Drive Supply Input
Voltage
1.0.7
1.0.8
VBDS
– 0.3
55
V
|VS – VBDS|<6.8V
Current
IBDS
–
–
–
Feedback Input
Voltage
1.0.9
VFB
– 0.3
6.8
V
1.0.10 Current
SI_Enable Input
IFB
–
–
–
(TLE6389G50-1,
TLE6389G33-1
only)
1.0.11 Voltage
VSI_ENAB – 0.3
6.8
V
LE
1.0.12 Current
ISI_ENABL
–
–
–
E
SI_GND Input
(TLE6389G50-1,
TLE6389G33-1
only)
1.0.13 Voltage
VSI_GND – 0.3
60
V
1.0.14 Current
ISI_GND
–
–
–
Enable Input
Target Datasheet Rev. 1.7
4
2001-09-17
TLE 6389
1
Absolute Maximum Ratings (cont’d)
Parameter Symbol Limit Values Unit Remarks
Item
min.
max.
1.0.15 Voltage
VENABLE – 0.3
60
V
(TLE6389G50,
TLE6389G33,
TLE6389GV only)
1.0.16 Current
IENABLE
–
–
–
Sense Input
1.0.17 Voltage
1.0.18 Current
VSI
– 0.3
60
V
ISI
–
–
–
Sense Output
1.0.19 Voltage
1.0.20 Current
VSO
– 0.3
6.8
V
ISO
–
–
–
VOUT Input
1.0.21 Voltage
1.0.22 Current
VOUT
– 0.3
15
V
IOUT
–
–
–
Reset Delay Adjust Input
1.0.23 Voltage
1.0.24 Current
VRD
– 0.3
6.8
V
IRD
TBD
TBD
mA
Reset Output
1.0.25 Voltage
1.0.26 Current
VRO
– 0.3
6.8
V
IRO
-2
2
mA
Synchronization Input
1.0.27 Voltage
1.0.28 Current
VSYNC
– 0.3
6.8
V
ISYNC
TBD
TBD
mA
ESD-Protection (Human Body Model; R=1,5kΩ; C=100pF)
1.0.29 all pins to GND –2 kV
VHBM
2
Target Datasheet Rev. 1.7
5
2001-09-17
TLE 6389
1
Absolute Maximum Ratings (cont’d)
Item
Parameter
Symbol Limit Values Unit Remarks
min.
max.
Temperatures
1.0.30 Junction temperature
1.0.31 Storage temperature
Tj
– 40
– 50
150
150
°C
°C
–
–
Tstg
Note: Maximum ratings are absolute ratings; exceeding any one of these values may
cause irreversible damage to the integrated circuit.
Target Datasheet Rev. 1.7
6
2001-09-17
TLE 6389
2
Operating Range
Parameter
Item
Symbol Limit Values Unit Remarks
min.
5
max.
48
2.0.1
2.0.2
Supply voltage range
Junction temperature
VS
V
Tj
– 40
150
°C
Thermal Resistance
2.0.3
2.0.4
Junction ambient
Junction pin
Rthj-a
Rthj-p
180
K/W –
K/W –
TBD
3
Electrical Characteristics
5V< VS <48V; - 40°C< Tj <150°C;
all voltages with respect to ground; positive current defined flowing into the pin; unless otherwise specified
Item
Parameter
Symbol
Limit Values
Unit Test Condition
min. typ. max.
Current Consumption1) TLE6389 (variable)
3.0.1 Supply current into IS
VS
80
µA
VS = 13.5 V;
ENABLE = 5 V;
V
IOUT = 0 mA;
TJ = 25 °C;
3.0.2
110 µA
VS = 42 V;
V
ENABLE = 5 V;
IOUT = 0 mA;
TJ = 25 °C;
3.0.3
2
4
µA
µA
VENABLE=0V
3.0.4 FB current
IFB
V
ENABLE = 5 V;
TJ = 25 °C;
Target Datasheet Rev. 1.7
7
2001-09-17
TLE 6389
3
Electrical Characteristics (cont’d)
5V< VS <48V; - 40°C< Tj <150°C;
all voltages with respect to ground; positive current defined flowing into the pin; unless otherwise specified
Item
Parameter
Symbol
Limit Values
Unit Test Condition
min. typ. max.
Current Consumption TLE6389-50
3.0.5 Supply current into IS
VS
50
80
µA
µA
VS = 13.5 V;
ENABLE = 5 V;
IOUT = 0 mA;
TJ = 25 °C;
V
3.0.6
VS = 42 V;
V
ENABLE = 5 V;
IOUT = 0 mA;
TJ = 25 °C;
3.0.7
2
µA
µA
V
ENABLE=0V
3.0.8 FB current
IFB
50
V
V
ENABLE = 5 V;
OUT = 5 V;
TJ = 25 °C;
Current Consumption TLE6389-33
3.0.9 Supply current into IS
VS
80
µA
VS = 13.5 V;
V
ENABLE = 5 V;
IOUT = 0 mA;
TJ = 25 °C;
3.0.10
3.0.11
110 µA
VS = 42 V;
V
ENABLE = 5 V;
IOUT = 0 mA;
TJ = 25 °C;
2
µA
VENABLE=0V
Current Consumption TLE6389-50-1
Target Datasheet Rev. 1.7
8
2001-09-17
TLE 6389
3
Electrical Characteristics (cont’d)
5V< VS <48V; - 40°C< Tj <150°C;
all voltages with respect to ground; positive current defined flowing into the pin; unless otherwise specified
Item
Parameter
Symbol
Limit Values
min. typ. max.
50
Unit Test Condition
3.0.12 Supply current into IS
VS
µA
µA
µA
VS = 13.5 V;
IOUT = 0 mA;
TJ = 25 °C;
3.0.13
80
50
VS = 42 V;
IOUT = 0 mA;
TJ = 25 °C;
3.0.14 FB current
IFB
VOUT = 5 V;
TJ = 25 °C;
Current Consumption TLE6389-33-1
3.0.15 Supply current into IS
VS
80
µA
VS = 13.5 V;
IOUT = 0 mA;
TJ = 25 °C;
3.0.16
110 µA
VS = 42 V;
IOUT = 0 mA;
TJ = 25 °C;
3.0.17 FB current
IFB
15
µA
VOUT = 3.3 V;
TJ = 25 °C;
Buck-Controller
3.0.18 Output voltage
VOUT
4.85 5
5.15 V
5V Versions;
VS = 5.8 V to
48V; IOUT
=
TBDmA to 2A
(PWM Mode);
RSENSE = 0.05Ω;
RM1 = 0.25Ω;RL1
= 0.1Ω;
Target Datasheet Rev. 1.7
9
2001-09-17
TLE 6389
3
Electrical Characteristics (cont’d)
5V< VS <48V; - 40°C< Tj <150°C;
all voltages with respect to ground; positive current defined flowing into the pin; unless otherwise specified
Item
Parameter
Symbol
Limit Values
Unit Test Condition
min. typ. max.
3.0.19 Output voltage
VOUT
4.75 5
5.25 V
5V Versions;
VS = 5.8 V to
48V; IOUT = 0mA
to TBDA (PFM
Mode);RSENSE
0.05Ω; RM1
=
=
0.25Ω;RL1 =
0.1Ω;
3.0.20
3.8
V
5V Versions;
VS = 4.2 V to
5.8V; IOUT
=
0mA to 500mA;
RSENSE = 0.1Ω;
RM1 = 0.4Ω;RL1
= 0.1Ω;
3.0.21 Output voltage
3.0.22
VOUT
-3% 3.3 +3% V
-5% 3.3 +5% V
3.3V Versions;
VS = 5 V to 48V;
IOUT = TBDto 2A
(PWM Mode);
3.3V Versions;
VS = 5 V to 48V;
IOUT = 0mA to
TBD (PFM
Mode);
3.0.23 FB threshold
voltage
VFB,th
1.22 1.25 1.27 V
TLE6389GV
5
5
3.0.24 Output adjust range
3.0.25 Line regulation
5
15
1
V
TLE6389GV
0.7
20
mV/ TBD
V
3.0.26 Load regulation
30
mV/ IOUT = 5mA to
A
2A;
3.0.27 Gate driver,
P-gate to source
voltage (off)
V
VS
GDRV – 0
0.2
V
V
C
C
ENABLE = 5 V
BDS = 220 nF
GDRV = 5nF
Target Datasheet Rev. 1.7
10
2001-09-17
TLE 6389
3
Electrical Characteristics (cont’d)
5V< VS <48V; - 40°C< Tj <150°C;
all voltages with respect to ground; positive current defined flowing into the pin; unless otherwise specified
Item
Parameter
Symbol
Limit Values
Unit Test Condition
min. typ. max.
3.0.28 Gate driver,
P-gate to source
V
VS
GDRV – TBD
6.5
V
VENABLE = 5 V
C
C
BDS = 220 nF
GDRV = 5nF
voltage (on)
3.0.29 Gate driver,
peak charging
current
IGDRV
IGDRV
tr
TBD
TBD
70
A
3.0.30 Gate driver,
peak discharging
current
A
3.0.31 Gate driver,
ns
ns
nC
VENABLE = 5 V
rise time
C
C
BDS = 220 nF
GDRV = 5nF
3.0.32 Gate driver,
tf
100
VENABLE = 5 V
fall time
C
C
BDS = 220 nF
GDRV = 5nF
3.0.33 Gate driver,
QGDRV
50
70
gate charge
3.0.34 Current Limit
VLIM
=
100 130 mV
Threshold Voltage
VVS –
VCS
3.0.35 PWM to PFM
0.1*
ILIM
mA ILIM = VLIM
RSENSE
/
Threshold Current
3.0.36 PFM to PWM
toff_PFM
TBD
µs
Threshold Timing
3.0.37 Oscillator frequency fOSC
3.0.38 Maximum duty cycle dMAX
3.0.39 Minimum duty cycle dMIN
270 360 450 kHz PWM mode only
100
%
PWM mode only
PWM mode only
TBD %
3.0.40 SYNC capture
range
270 360 450 kHz PWM mode only
Target Datasheet Rev. 1.7
11
2001-09-17
TLE 6389
3
Electrical Characteristics (cont’d)
5V< VS <48V; - 40°C< Tj <150°C;
all voltages with respect to ground; positive current defined flowing into the pin; unless otherwise specified
Item
Parameter
Symbol
Limit Values
Unit Test Condition
min. typ. max.
Reset Generator
3.0.41 Reset threshold
VRT
0.9*
1.25
V
TLE6389GV
only; VOUT
decreasing
3.0.42 Reset threshold
hysteresis
VRT,hys
VRT
100
mV TLE6389GV
only
3.0.43 Reset threshold
3.5
4.5
2.8
2.9
10
3.65 3.8
4.65 4.8
2.95 3.1
3.05 3.2
V
5V Versions;
VOUT decreasing
3.0.44
V
5V Versions;
VOUT increasing
3.0.45 Reset threshold
3.0.46
VRT
V
3.3V Versions;
VOUT decreasing
V
3.3V Versions;
VOUT increasing
3.0.47 Reset pull up
RRO
20
40
kΩ
3.3V and 5V
Versions;
Internally
connected to
VOUT
3.0.48 Reset output High
VROH
0.8*
VOUT
V
3.3V and 5V
Versions;IROH=0
mA
voltage
3.0.49 Reset output Low
VROL
0.2 0.4
0.2 0.4
4
V
IROL=1mA;
2.5V < VOUT
VRT
voltage
<
3.0.50
V
IROL=0.2mA;
1V < VOUT
2.5V
<
3.0.51 Reset delay
Id
µA
VD = 1V
charging current
Target Datasheet Rev. 1.7
12
2001-09-17
TLE 6389
3
Electrical Characteristics (cont’d)
5V< VS <48V; - 40°C< Tj <150°C;
all voltages with respect to ground; positive current defined flowing into the pin; unless otherwise specified
Item
Parameter
Symbol
Limit Values
min. typ. max.
tbd
Unit Test Condition
3.0.52 Upper reset timing
VRDO
VRDL
td
V
V
--
--
threshold
3.0.53 Lower timing
tbd
threshold
3.0.54 Reset delay time
35
50
70
10
1
ms
µs
µs
CRD = 100nF
CRD = 100nF
CRD = 100nF
3.0.55 Reset reaction time trr
3.0.56 Reset Output delay tROd
ENABLE Input
3.0.57 Enable ON-
threshold
VENABLE,
2
V
ON
3.0.58 Enable OFF-
threshold
VENABLE,
OFF
0.8
5
V
3.0.59 H-level input current IENABLE,O
µA
µA
N
3.0.60 L-level input current IENABLE,O
2
FF
SI_ENABLE Input
3.0.61 Enable ON-
threshold
VENABLE,
2
V
ON
3.0.62 Enable OFF-
threshold
VENABLE,
0.8
5
V
OFF
3.0.63 H-level input current IENABLE,O
µA
N
Target Datasheet Rev. 1.7
13
2001-09-17
TLE 6389
3
Electrical Characteristics (cont’d)
5V< VS <48V; - 40°C< Tj <150°C;
all voltages with respect to ground; positive current defined flowing into the pin; unless otherwise specified
Item
Parameter
Symbol
Limit Values
min. typ. max.
2
Unit Test Condition
3.0.64 L-level input current IENABLE,O
µA
FF
SI_GND Input
3.0.65 Switch ON
resistance
RSW
100
Ω
Tj=25°C;
ISI_GND = TBDuA
Battery Voltage Sense
3.0.66 Sense threshold
Vsi, high
Vsi, hys
RSO
1.13 1.25 1.37 V
high to low
3.0.67 Sense threshold
–
100 –
mV
–
hysteresis
3.0.68 S ense out pull up
10
20
40
kΩ
3.3V and 5V
Versions;
Internally
connected to
VOUT
3.0.69 Sense out output
VSOH
VSOL
0.8*
VOUT
V
V
ISOH=0mA
High voltage
3.0.70 Sense out output
0.2 0.4
ISOL=1mA;
Low voltage
2.5V < VOUT;
VSI < 1.13 V
3.0.71
0.2 0.4
V
ISOL=0.2mA;
1V<VOUT<2.5V;
VSI < 1.13 V
3.0.72 Sense input current ISI
– 1
0.1
1
µA
–
Thermal Shutdown
Target Datasheet Rev. 1.7
14
2001-09-17
TLE 6389
3
Electrical Characteristics (cont’d)
5V< VS <48V; - 40°C< Tj <150°C;
all voltages with respect to ground; positive current defined flowing into the pin; unless otherwise specified
Item
Parameter
Symbol
Limit Values
Unit Test Condition
min. typ. max.
3.0.73 Thermal shutdown TjSD
junction
150 175 200 °C
temperature
3.0.74 Temperature
hysteresis
DT
30
K
1)
The device IS and IFB current measurements exclude MOSFET driver currents. Contribution of MOSFET
driver currents are discussed in application section.
Target Datasheet Rev. 1.7
15
2001-09-17
TLE 6389
4
Detailed Description
The TLE6389 family is a family of step-down DC-DC controllers designed primarily for
use in high voltage applications such as automotive. Using an external MOSFET and
current-sense resistor allows design flexibility and the improved efficiencies associated
with high-performance P-channel MOSFETs. A unique, current-limited, pulse-width
(PWM)/pulse-frequency-modulated (PFM) control scheme gives these devices excellent
efficiency over load ranges up to three decades, while drawing less than 100µA under
no load. This wide dynamic range optimizes the TLE6389 for automotive applications,
where load currents can vary considerably as individual circuit blocks are turned on and
off to conserve energy. Operation to a 100% duty cycle allows the lowest possible
dropout voltage, allowing operation during cold cranking. High switching frequencies and
a simple circuit topology minimize PC board area and component costs.
The output voltage is sensed either by an internal voltage divider connected to the FB
pin (TLE6389-50 and TLE6389-33) or an external divider returned to the FB pin
(TLE6389).
RSENSE
=
M1
L1 = 47 µH
VIN
VOUT
IOUT
0.05
CIN1
100
=
COUT
100
=
F
CBDS
=
µF
D1
µ
220 nF
M1: Infineon SPD09P06PL
D1: Motorola MBRD360
L1: Coilcraft DO3340P-473
Cin1: TBD
11
BDS
14
12
GDRV
2
CS
3
FB
13
7
VOUT
VS
RSI1
=
CIN2
=
9
SO
Cout: Low ESR Tantalum
TLE6389G50
400k
220nF
10
SI
RO
RD
RSI2=
SI_GND ENABLE
SYNC GND
100k
6
1
5
4
8
CRD =100nF
ON OFF
TLE6389G50 Application Circuit
Target Datasheet Rev. 1.7
16
2001-09-17
TLE 6389
RSENSE
=
M1
L1 = 47 µH
VIN
VOUT
0.05
CIN1
100
=
COUT
=
F
RSO
=
RRO
=
CBDS
=
µF
D1
100
µ
20k
20k
220 nF
11
BDS
VS
14
12
GDRV
3
CS
VOUT
SO
13
7
9
10
2
RFB1
=
RSI1
=
CIN2
=
RO
FB
TBDk
TLE6389GV
400k
220nF
SI
RSI2=
SI_GND ENABLE
SYNC GND
RD
RFB2=
100k
5
4
6
1
8
47k
ON OFF
CRD =100nF
M1: Infineon SPD09P06PL
D1: Motorola MBRD340
L1: Coilcraft DO3340P-473
Cin1: TBD
Cout: Low ESR Tantalum
TLE6389GV Application Circuit
RSENSE
=
M1
L1 = 47 µH
VIN
VOUT
IOUT
0.05
CIN1
100
=
COUT
100
=
F
CBDS
=
µF
D1
µ
220 nF
M1: Infineon SPD09P06PL
D1: Motorola MBRD360
L1: Coilcraft DO3340P-473
Cin1: TBD
11
BDS
14
12
GDRV
2
CS
3
FB
13
7
VOUT
VS
RSI1
=
CIN2
=
9
SO
Cout: Low ESR Tantalum
400k
220nF
TLE6389G50-1
10
SI
RO
RD
RSI2=
SI_GND SI_ENABLE SYNC GND
100k
6
1
5
4
8
CRD =100nF
ON OFF
TLE6389G50-1 Application Circuit
Target Datasheet Rev. 1.7
17
2001-09-17
TLE 6389
4.1
Operating Modes
4.1.1
PWM Control Scheme
The TLE6389 uses a slope-compensated, current-mode PWM controller capable of
achieving 100% duty cycle. The device uses an oscillator-triggered, minimum on-time,
current-mode control scheme. The minimum on-time is approximately 200ns unless in
dropout. The maximum on-time is greater than 1/fOSC, allowing operation to 100% duty
cycle. Current-mode feedback provides cycle-by-cycle current limiting for superior load-
and line-response and protection of the external MOSFET and rectifier diode. At each
falling edge of the internal oscillator, the oscillator cell sends a PWM ON signal to the
control and drive logic, turning on the external P-channel MOSFET. This allows current
to ramp up through the inductor to the load, and stores energy in a magnetic field. The
switch remains on until either the current-limit comparator is tripped or the PWM
comparator signals that the output is in regulation. When the switch turns off during the
second half of each cycle, the inductor’s magnetic field collapses, releasing the stored
energy and forcing current through the rectifier diode to the output-filter capacitor and
load. The output-filter capacitor stores charge when the inductor current is high and
releases it when the inductor current is low, thus smoothing the voltage across the load.
During normal operation, the TLE6389 regulates output voltage by switching at a
constant frequency and then modulating the power transferred to the load each cycle
using the PWM comparator. A multi-input comparator sums three weighted differential
signals: the output voltage with respect to the reference, the main switch current sense,
and the slope-compensation ramp. It modulates output power by adjusting the inductor-
peak current during the first half of each cycle, based on the output-error voltage.
4.1.2
100% Duty-Cycle Operation and Dropout
The TLE6389 operates with a duty cycle up to 100%. This feature extends allows to
operate with the lowest possible drop at low battery voltage as it occurs at cold ambient
temperatures. The MOSFET is turned on continuously when the supply voltage
approaches the output voltage. This services the load when conventional switching
regulators with less than 100% duty cycle would fail. Dropout voltage is defined as the
difference between the input and output voltages when the input is low enough for the
output to drop out of regulation. Dropout depends on the MOSFET drain-to-source on-
resistance, current-sense resistor, and inductor series resistance, and is proportional to
the load current:
Dropout Voltage = IOUT x (RDS(ON) + RSENSE + RINDUCTOR
)
Target Datasheet Rev. 1.7
18
2001-09-17
TLE 6389
4.1.3
PWM/PFM Operation
This control scheme overrides PWM mode and places the TLE6389 in PFM mode at
light loads to improve efficiency and reduce quiescent current to less than 100µA. The
pulse-skipping PFM operation is initiated when the peak inductor current drops below 0.1
x Ilimit. During PFM operation, the TLE6389 switches only as needed to service the load,
reducing the switching frequency and associated losses in the external switch, the
rectifier diode, and the external inductor. During PFM mode, a switching cycle initiates
when the PFM comparator senses that the output voltage has dropped too low. The P-
channel MOSFET switch turns on and conducts current to the output-filter capacitor and
load until the inductor current reaches the PFM peak voltage limit. Then the switch turns
off and the magnetic field in the inductor collapses, forcing current through the
synchronous rectifier to the output filter capacitor and load. Then the TLE6389 waits until
the PFM comparator senses a low output voltage again.
Output ripple is higher during PFM operation. A larger output-filter capacitor can be used
to minimize ripple.
4.2
SYNC Input and Frequency Control
The TLE6389’s internal oscillator is set for a fixed-switching frequency of 360kHz or can
be synchronized to an external clock. Do not leave SYNC unconnected. Connecting
SYNC to GND enables PWM/PFM operation to reduce supply current at light loads.
SYNC is a negative-edge triggered input that allows synchronization to an external
frequency ranging between 270kHz and 450kHz. When SYNC is clocked by an external
signal, the converter operates in PWM mode until the load current drops below the PWM
to PFM threshold. Thereafter the converter continues operation in PFM mode.
4.3
Shutdown Mode
Connecting ENABLE to GND places the TLE6389GV, TLE6389G33 and TLE6389G50
in shutdown mode. In shutdown, the reference, control circuitry, external switching
MOSFET, and the oscillator are turn off and the output falls to 0V. Connect ENABLE to
IN for normal operation.
4.4
SI_Enable
Connecting SI_ENABLE to 5V causes SI_GND to have low impedance. Thus the SI
comparator is operational and ca be used to monitor the battery voltage. SO output
signal is valid. Connecting SI_ENABLE to GND causes SI_GND to have high
impedance. Thus the SI comparator is not able to monitor the battery voltage. SO output
signal is invalid.
Target Datasheet Rev. 1.7
19
2001-09-17
TLE 6389
4.5
Quiescent Current
The device’s typical quiescent current is 50µA. However, actual applications draw
additional current to supply MOSFET switching currents, FB pin current, or external
feedback resistors (if used), and both the diode and capacitor leakage currents. For
example, with VS at 13.5V and VOUT at 5V, typical no-load supply current for the entire
circuit is TBDµA. When designing a circuit for high-temperature operation, select a
Schottky diode with low reverse leakage.
5
Application Information
5.1
Output Voltage Selection (TLE6389GV only)
Select an output voltage between 5V and 15V by connecting FB to a resistor-divider
between the output and GND. Select feedback resistor R2 in the 5kΩ to 500kΩ range.
R1 is then given by:
R1 = R2 [(VOUT / VFB) - 1]
where VFB = 1.25V. Add a small ceramic capacitor around 47pF to 100pF in parallel
with R1 to compensate for stray capacitance at the FB pin and output capacitor
equivalent series resistance (ESR).
5.2
Output Capacitor Selection
Choose input- and output-filter capacitors to service inductor currents with acceptable
voltage ripple. The input-filter capacitor also reduces peak currents and noise at the
voltage source. In addition, connect a low-ESR bulk capacitor (>10µF suggested) to the
input. Select this bulk capacitor to meet the input ripple requirements and voltage rating,
rather than capacitor size. Use the following equation to calculate the maximum RMS
input current:
IRMS = IOUT[VOUT (VIN - VOUT)]1/2 · VIN
When selecting an output capacitor, consider the output- ripple voltage and approximate
it as the product of the ripple current and the ESR of the output capacitor.
VRIPPLE = [VOUT (VIN - VOUT)] / [2 · fOSC(L) (VIN)] · ESRCOUT
where ESRCOUT is the equivalent-series resistance of the output capacitor. Higher
values of COUT provide improved output ripple and transient response. Lower oscillator
frequencies require a larger-value output capacitor. Verify capacitor selection with light
loads during PFM operation, since output ripple is higher under these conditions. Low-
ESR capacitors are recommended. Capacitor ESR is a major contributor to output ripple
(usually more than 60%). Ordinary aluminum-electrolytic capacitors have high ESR and
should be avoided. Low-ESR aluminum-electrolytic capacitors are acceptable and
relatively inexpensive. Low-ESR tantalum capacitors are better and provide a compact
Target Datasheet Rev. 1.7
20
2001-09-17
TLE 6389
solution for space-constrained surface-mount designs. Do not exceed the ripple-current
ratings of tantalum capacitors. Ceramic capacitors have the lowest ESR overall.
Target Datasheet Rev. 1.7
21
2001-09-17
TLE 6389
6
Package Outlines
Dimensions in mm
Target Datasheet Rev. 1.7
22
2001-09-17
TLE 6389
Published by Infineon Technologies AG,
St.-Martin-Strasse 53
D-81541 München
© Infineon Technologies AG2000
All Rights Reserved.
Attention please!
The information herein is given to describe certain components and shall not be considered as warranted charac-
teristics.
Terms of delivery and rights to technical change reserved.
We hereby disclaim any and all warranties, including but not limited to warranties of non-infringement, regarding
circuits, descriptions and charts stated herein.
Infineon Technologiesis an approved CECC manufacturer.
Information
For further information on technology, delivery terms and conditions and prices please contact your nearest Infi-
neon Technologies Office in Germany or our Infineon Technologies Representatives worldwide (see address list).
Warnings
Due to technical requirements components may contain dangerous substances. For information on the types in
question please contact your nearest Infineon Technologies Office.
Infineon Technologies Components may only be used in life-support devices or systems with the express written
approval of Infineon Technologies, if a failure of such components can reasonably be expected to cause the failure
of that life-support device or system, or to affect the safety or effectiveness of that device or system. Life support
devices or systems are intended to be implanted in the human body, or to support and/or maintain and sustain
and/or protect human life. If they fail, it is reasonable to assume that the health of the user or other persons may
be endangered.
Target Datasheet Rev. 1.7
23
2001-09-17
This datasheet has been download from:
www.datasheetcatalog.com
Datasheets for electronics components.
相关型号：
TLE6389G50NTMA1
Switching Controller, Current-mode, 420kHz Switching Freq-Max, PDSO14, PLASTIC, DSO-14
INFINEON
TLE6389GVT
Switching Controller, Current-mode, 420kHz Switching Freq-Max, PDSO14, PLASTIC, DSO-14
INFINEON
©2020 ICPDF网 联系我们和版权申明