ETC FP6190

FP6190
1.2A, 23V, 1.4MHz Step-Down Converter
General Description
The FP6190 is a buck regulator with a built-in internal power MOSFET. It can provide 1.2A
continuous output current over a wide input supply range with excellent load and line regulation.
Current mode operation provides fast transient response and eases loop stabilization. This device
includes cycle-by-cycle current limiting and thermal shutdown protection. Internal soft-start reduces the
stress on the input source at power-on. The FP6190 requires a minimum number of readily available
external components to complete a 1.2A buck regulator solution.
Features











1.2A Output Current
0.35Ω Internal High Side Power MOSFET Switch
Stable with Low ESR Output Ceramic Capacitors
Up to 92% Efficiency
0.1μA Shutdown Mode Current
Fixed 1.4MHz Frequency
Thermal Shutdown
Cycle-by-Cycle Over Current Protection
Wide 4.75 to 23V Operating Input Range
Output Adjustable From 0.81 to 15V
Available in TSOT23-6L / SOT23-6L Packages
Applications
 Distributed Power Systems
 Battery Charger
 Pre-Regulator for Linear Regulators
 DSL Modems
Typical Application Circuit
This datasheet contains new product information. Feeling Technology reserves the rights to modify the product specification without notice.
No liability is assumed as a result of the use of this product. No rights under any patent accompany the sales of the product.
Rev. 0.61
Website: http://www.feeling-tech.com.tw
1/13
FP6190
Function Block Diagram
IN
Internal
Regulator
Slope
Compensation
Current
Sense
5V
EN
Enable
Control
BS
Oscillator
1.4MHz/460KHz
SW
Control
Logic
UVLO
Current
Comparator
Compensation
0.4V
GND
Frequency
Foldback
Comparator
0.8V
Error
Amplifier
SS
FB
This datasheet contains new product information. Feeling Technology reserves the rights to modify the product specification without notice.
No liability is assumed as a result of the use of this product. No rights under any patent accompany the sales of the product.
Website: http://www.feeling-tech.com.tw
Rev. 0.61
2/13
FP6190
Pin Descriptions
TSOT23-6L / SOT23-6L
Name
No. I / O
Description
AK962
BS
1
P
Bootstrap
GND
2
P
IC Ground
FB
3
I
Error Amplifier Compensation Output
EN
4
I
Enable / UVLO
IN
5
P
Supply Voltage
SW
6
O
Switch
Marking Information
TSOT23-6L / SOT23-6L
AK962
Lot Number
Year
Part Number Code
Lot Number: Wafer lot number’s last two digits
For Example: 132386TB  86
Year: Production year’s last digit
Part Number Code: Part number identification code for this product. It should be always “AK”.
This datasheet contains new product information. Feeling Technology reserves the rights to modify the product specification without notice.
No liability is assumed as a result of the use of this product. No rights under any patent accompany the sales of the product.
Website: http://www.feeling-tech.com.tw
Rev. 0.61
3/13
FP6190
Ordering Information
Operating Temperature
Package
MOQ
Description
FP6190hR-G1
Part Number
-40°C ~ +85°C
TSOT23-6L
3000EA
Tape & Reel
FP6190LR-G1
-40°C ~ +85°C
SOT23-6L
3000EA
Tape & Reel
Absolute Maximum Ratings
Parameter
Symbol
Conditions
Min.
Typ.
Max.
Unit
Supply Voltage
VIN
-0.3
26
V
Supply Voltage
Vsw
-1
VIN +0.3
V
Bootstrap Voltage
VBS
Vsw -0.3
Vsw +6
V
-0.3
6
V
+150
°C
+150
℃
All Other Pins
Junction Temperature
TJ
Storage Temperature
TS
Thermal Resistance
Thermal Resistance
-65
θJA
TSOT23-6L
220
℃/W
θJC
TSOT23-6L
110
℃/W
θJA
SOT23-6L
220
℃/W
θJC
SOT23-6L
110
℃/W
+85
℃
+260
℃
Operating Temperature
-40
Lead Temperature (soldering, 10
sec)
Suggested IR Re-flow Soldering Curve
This datasheet contains new product information. Feeling Technology reserves the rights to modify the product specification without notice.
No liability is assumed as a result of the use of this product. No rights under any patent accompany the sales of the product.
Website: http://www.feeling-tech.com.tw
Rev. 0.61
4/13
FP6190
Recommended Operating Conditions
Parameter
Supply Voltage
Symbol
Conditions
VIN
Operating Temperature
Ambient Temperature
Min.
Typ.
Max.
Unit
4.75
23
V
-40
85
°C
DC Electrical Characteristics (VIN=12V, TA= 25°C, unless otherwise noted)
Parameter
Symbol
Test Conditions
ISB
VEN=2V, VFB=1.0V
Shutdown Supply Current
IST
VEN=0
Feedback Voltage
VFB
4.5V<VIN<24V
Feedback Current
IFB
VFB=0.8V
Switch ON Resistance
RON
Standby Current
Switch Leakage Current
IIL
Current Limit
ICL
Oscillation Frequency
fOSC
Short Circuit Oscillation Frequency
fSC
Min.
0.78
Typ.
Max.
Unit
0.8
1.0
mA
0.1
1.0
µA
0.8
0.82
V
0.1
µA
0.35
Ω
VEN=0, VSW=0V
10
1.5
1.2
VFB=0V
1.4
µA
A
1.7
460
MHz
KHz
Maximum Duty Cycle
DMAX
VFB=0.6V
87
%
Minimum On Time
TON
VFB=1.5V
100
ns
VUVLO
VEN Rising
Under Voltage Lockout Threshold
Under Voltage Lockout Threshold
Hysteresis
2.5
2.8
3.1
150
VHYS
EN Input Low Voltage
mV
0.4
EN Input High Voltage
1.2
EN Input Current
IEN
Thermal Shutdown
TTS
V
V
V
VEN=2V
2.1
VEN=0V
0.1
150
µA
°C
This datasheet contains new product information. Feeling Technology reserves the rights to modify the product specification without notice.
No liability is assumed as a result of the use of this product. No rights under any patent accompany the sales of the product.
Website: http://www.feeling-tech.com.tw
Rev. 0.61
5/13
FP6190
Function Description
The FP6190 is a current-mode step-down DC / DC converter that provides excellent transient
response with no extra external compensation components. It regulates input voltages from 4.5V to
24V down to an output voltage as low as 0.81V with maximum 1.2A load current. and operates at a
high 1.4MHz operating frequency to ensure a compact, high-efficiency design with excellent AC and
DC performance.The output voltage is measured at FB pin through a resistive voltage divider and
amplified by the internal error amplifier. The converter uses an internal n-channel MOSFET switch to
step-down the input voltage to the regulated output voltage. Since the n-channel MOSFET requires a
gate voltage greater than the input voltage, a boost capacitor connected between SW and BS drives
the MOS gate. The capacitor is internally charged while the MOS switch is off.
Output Voltage (VOUT)
The output voltage is set using a resistive voltage divider from the output voltage to FB. The
voltage divider divides the output voltage down by the ratio:
VFB  VOUT 
R2
R1  R2
Thus the output voltage is:
VOUT  VFB 
R1  R2
R2
Enable Mode / Shutdown Mode
Drive EN Pin to ground to shut down the FP6190. Shutdown mode forces the internal power
MOSFET off, turns off all internal circuitry, and reduces the VIN supply current to 0.1μA (typ.). The EN
Pin rising threshold is 1.0V (typ.). Before any operation begins, the voltage at EN pin must exceed 1.0V
(typ.).
The EN pin input has 100mV hysteresis.
Boost High-Side Gate Drive (BST)
Since the MOSFET requires a gate voltage greater than the input voltage, user should connect a
flying bootstrap capacitor between SW and BS pin to provide the gate-drive voltage to the high-side
n-channel MOSFET switch. The capacitor is charged by the internally regulator periodically when SW
pin is pulled to ground. During startup, an internal low-side switch pulls SW to ground and charges the
BST capacitor to internally regulator output voltage. Once the BST capacitor is charged, the internal
low-side switch is turned off and the BST capacitor provides the necessary enhancement voltage to
turn on the high-side switch.
This datasheet contains new product information. Feeling Technology reserves the rights to modify the product specification without notice.
No liability is assumed as a result of the use of this product. No rights under any patent accompany the sales of the product.
Website: http://www.feeling-tech.com.tw
Rev. 0.61
6/13
FP6190
Thermal Shutdown Protection
The FP6190 features integrated thermal shutdown protection. Thermal shutdown protection limits
allowable power dissipation (PD) in the device and protects the device in the event of a fault condition.
When the IC junction temperature exceeds +150°C, an internal thermal sensor signals the shutdown
logic to turn off the internal power MOSFET and allow the IC cooling down. The thermal sensor turns
the internal power MOSFET back on after the IC junction temperature cools down to + 110°C, resulting
in a pulsed output under continuous thermal overload conditions.
This datasheet contains new product information. Feeling Technology reserves the rights to modify the product specification without notice.
No liability is assumed as a result of the use of this product. No rights under any patent accompany the sales of the product.
Website: http://www.feeling-tech.com.tw
Rev. 0.61
7/13
FP6190
Application Information
Input Capacitor Selection
The input current to the step-down converter is discontinuous, therefore a capacitor is required to
supply the AC current to the step-down converter while maintaining the DC input voltage. Use low ESR
capacitors for the best performance. Ceramic capacitors are preferred, but tantalum or low-ESR
electrolytic capacitors may also suffice.
The input capacitor can be electrolytic, tantalum or ceramic. When electrolytic or tantalum
capacitors are used, a small, high quality 0.1μF ceramic capacitor should be placed beside the IC as
possible.
When using ceramic capacitors, make sure that they have enough capacitance to provide
sufficient charge to prevent excessive voltage ripple at converter input. The input voltage ripple can be
estimated by
C IN 
IO
 D(1  D)
f  VIN
Inductor Selection
The inductor is required to supply constant current to the output load while being driven by the
switched input voltage. A larger value inductor will result in less ripple current that will result in lower
output ripple voltage. However, the larger value inductor will have a larger physical size, higher series
resistance, and/or lower saturation current. A good rule for determining the inductance to use is to
allow the peak-to-peak ripple current in the inductor to be approximately 30% of the maximum switch
current. Also, make sure that the peak inductor current is below the maximum switch current limit. The
inductance value can be calculated by
L
VO  VD
 (1  D)
IO f
Where r is the ripple current ratio
RMS current in inductor ILrms  IO 1 
2
12
Output Capacitor Selection
The output capacitor is required to maintain the DC output voltage. Ceramic, tantalum, or low
ESR electrolytic capacitors are recommended. Low ESR capacitors are preferred to keep the output
voltage ripple low. The output voltage ripple can be estimated by:
This datasheet contains new product information. Feeling Technology reserves the rights to modify the product specification without notice.
No liability is assumed as a result of the use of this product. No rights under any patent accompany the sales of the product.
Website: http://www.feeling-tech.com.tw
Rev. 0.61
8/13
FP6190
VOUT 
VOUT  VIN  VOUT  
1
  ESR 


f  L  VIN
8
f
C OUT





In the case of ceramic capacitors, the output ripple is dominated by the capacitance value
because of its low ESR. In the case of tantalum or electrolytic capacitors, the capacitor high ESR
dominates the output ripple. Followings are equations for determining appropriate capacitor
parameters.
Ⅰ. Ceramic capacitors: choose capacitance value
C OUT 
VOUT
2
8  f  L  VOUT

V
 1  OUT
VIN




Ⅱ. Tantalum or electrolytic capacitors: choose capacitor with ESR value
ESR 
VOUT  f  L  VIN
VOUT  VIN  VOUT 
PC Board Layout Checklist
1. The power traces, consisting of the GND, SW and VIN traces, should be kept short, direct and
wide.
2. Place CIN near IN pin as closely as possible to maintain input voltage steady and filter out the
pulsing input current.
3. The resistive divider R1 and R2 must be connected directly to FB pin as closely as possible.
4. FB is a sensitive node. Please keep it away from switching node SW. A good approach is to
route the feedback trace on another layer and have a ground plane between the top and
feedback trace routing layer. This reduces EMI radiation on to the DC-DC converter’s own
voltage feedback trace.
This datasheet contains new product information. Feeling Technology reserves the rights to modify the product specification without notice.
No liability is assumed as a result of the use of this product. No rights under any patent accompany the sales of the product.
Website: http://www.feeling-tech.com.tw
Rev. 0.61
9/13
FP6190
Suggested Layout
This datasheet contains new product information. Feeling Technology reserves the rights to modify the product specification without notice.
No liability is assumed as a result of the use of this product. No rights under any patent accompany the sales of the product.
Website: http://www.feeling-tech.com.tw
Rev. 0.61
10/13
FP6190
Typical Application
VIN
12V
C1
10µF
C3
10nF
VOUT
3.3V
L1 4.7µH
1 BST
SW
6
FP6190
2
3
GND
FB
IN
EN
R1
49.9K
5
D1
SK34
4
C2
22µF
R2
16.2K
ON
OFF
This datasheet contains new product information. Feeling Technology reserves the rights to modify the product specification without notice.
No liability is assumed as a result of the use of this product. No rights under any patent accompany the sales of the product.
Website: http://www.feeling-tech.com.tw
Rev. 0.61
11/13
FP6190
Package Outline
TSOT23-6L
Unit: mm
Symbols
Min. (mm)
Max. (mm)
A
0.750
0.800
A1
0.000
0.050
A2
0.700
0.775
b
0.350
0.500
c
0.100
0.200
D
2.800
3.000
E
2.600
3.000
E1
1.500
1.700
e
0.950 BSC
e1
1.900 BSC
L
0.370
0.600
L1
0.600 REF
L2
0.250 BSC
R
0.100
R1
0.100
0.250
θ°
0°
8°
θ1
4°
12°
Note:
1. Dimension “D” does not include molding flash, protrusions or gate burrs.
2. Dimension “E1” does not include inter-lead flash or protrusions.
This datasheet contains new product information. Feeling Technology reserves the rights to modify the product specification without notice.
No liability is assumed as a result of the use of this product. No rights under any patent accompany the sales of the product.
Website: http://www.feeling-tech.com.tw
Rev. 0.61
12/13
FP6190
SOT23-6L
Unit: mm
Symbols
Min. (mm)
Max. (mm)
A
1.050
1.450
A1
0.050
0.150
A2
0.900
1.300
b
0.300
0.500
c
0.080
0.220
D
2.900 BSC
E
2.800 BSC
E1
1.600 BSC
e
0.950 BSC
e1
1.900 BSC
L
0.300
0.600
L1
0.600 REF
L2
0.250 BSC
θ°
0°
8°
θ1°
3°
7°
θ2°
6°
15°
Note:
1. Package dimensions are in compliance with JEDEC outline: MO-178 AB.
2. Dimension “D” does not include molding flash, protrusions or gate burrs.
3. Dimension “E1” does not include inter-lead flash or protrusions.
This datasheet contains new product information. Feeling Technology reserves the rights to modify the product specification without notice.
No liability is assumed as a result of the use of this product. No rights under any patent accompany the sales of the product.
Website: http://www.feeling-tech.com.tw
Rev. 0.61
13/13