AMS AMS34063C

AMS34063
GENERAL DESCRIPTION
FEATURES
is a monolithic control
‹
3V to 40V Input Voltage Operation.
circuit containing the primary functions required
‹
Internal 1.5A Peak Current Switch.
for DC/DC converters. The device consists of an
‹
Internal ±2% Reference.
internal temperature compensated reference,
‹
Low Quiescent Current .
comparator, controlled duty cycle oscillator with
‹
Frequency Operation Up to 100KHz.
an active current limit circuit, driver and high
‹
Low Dropout Operation: 100% Duty Cycle
current output switch. This device is specifically
‹
Current Limiting.
designed to be incorporated in step-down,
‹
Standard DIP8 and SOP8 Packages
The
AMS34063
step-up and voltage-inverting applications with a
minimum number of external components. The
Applications
±2% internal reference and low quiescent current
of 1.6mA are among the improvements of the
‹
DC-DC Converter Module
device over the competition
‹
ADSL Modems
‹
Hub.
‹
Battery
Chargers
Functional Diagram
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AMS34063
Pin Description
Symbol
Pin NO.
Description
SC
1
1.5A switch collector
SE
2
Darlington switch emitter
TC
3
Oscillator timing capacitor
GND
4
Power GND
FB
5
Feedback comparator inverting input
VCC
6
Power supply input
IPK
7
Highside current sense input, VCC - VIPK=300mV
DRI
8
Drive collector
Ordering Information
ORDERI NG NUM BER
PACKAGE
AMS34063
SOP8
AMS34063A
DIP8
Absolute Maximum Ratings
Supply Voltage
……………….……………………. ………………………………… ……40V
Comparator Input Voltage Range ……………………….……..………………………-0.3V~40V
Switch Collector Voltage
……………………………………………………………….
40V
Switch Emitter Voltage
…………………………………………………………………… 40V
Switch Collector to Emitter Voltage …………………………………………………….. .40V
Driver Collector Voltage
…………………………………………………………………….40V
Switch Current………………………………………………………………………………..1.5A
Power Dissipation and Thermal Characteristics
DIP Package
Ta= 25°C…………………………………………………………..1.0W
Thermal Resistance ……………………………………......
100°C /W
SO Package
Ta= 25°C
……………………………………………………625mW
Thermal Resistance ………………………………………...160°C /W
Operating Junction Temperature
………..…………………………………………………125°C
Operating Ambient Temperature Range ……...…………………………………….. 0°C~70°C
Storage Temperature Range
……………....……………………………………...
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- 65°C~150°C
AMS34063
Electrical Characteristics (Vcc= 5V, Ta=25°C (unless otherwise specified.)
Parameter
Test Condictions
Symbol
MIN. TYP. MAX. Unit
Oscillator
Frequency
VPIN5 = 0V ,CT = 1nF
Charging Current
5.0V~VCC~40V
Discharge Current
5.0V~VCC~40V
Voltage Swing
PIN 3
Discharge to Charge Current
Ratio
Current Limit Sense Voltage
fOSC
ICHG
IDISCHG
24
35
46
KHZ
24
35
46
µA
140
220
260
µA
0.6
VOSC
VIPK(SENSE) =VCC
IDISCHG/ ICHG
ICHG=IDISCHG
VIPK(SENSE)
ISW=1.0A;
VCE(SAT)
V
6.0
250
320
400
mV
Output Switch
Saturation Voltage, Darlington
Connection
Saturation Voltage
1.0
1.3
V
0.45
0.7
V
VC(DRIVER)=VC(SWITCH)
ISW=1.0A; IC(DRIVER)=50mA
(Forced ß=20)
DC Current Gain
ISW=1.0A; VCE=5.0V
Collector Off-State Current
VCE=40V
VCE (SAT)
hFE
50
75
10
IC(OFF)
nA
Comparator
Threshold Voltage
0°C~Ta~70°C
VFB
Threshold Voltage
Threshold Voltage Line
1.225 1.25
1.19
1.275
V
1.31
V
3.0V~VCC~40V
REGLINE
0.1 0.3
mV/V
Input Bias Current
VIN=0V
IIB
0.4 1
µA
Supply current
VIPK(SENSE)=VCC
ICC
Regulation
VPIN 5>VFB
5.0V~VCC~40V
CT=0.001µF, PIN 2=GND
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4
Ma
Typical Performance Characteristics
AMS34063
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AMS34063
Application Information
Design Formula Table
FMIN - Minimum desired output switching
VSAT
= Saturation voltage of the output
switch.
frequency at the selected values for VIN
and lOUT
VF
= voltage drop of the ringback rectifier
VRIPPLE (P-P) - Desired peak-to-peak output
ripple voltage.In practice, the calculated
The following power supply characteristics must
be chosen:
VIN
value will need to be increased due to the
capacitor equivalent series resistance
-Nominal input voltage.
and board layout. The ripple voltage
VOUT
-Desired output voltage,
lOUT
|VOUT| =1.25 (1 + RB/RA)
- Desired output current.
should be kept to a low value since it will
directly effect the line and load regulation.
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AMS34063
Application Examples
Line Regulation
VIN = 10V ~20V @ IO =500mA
40mV
Load Regulation
VIN = 15V, @ IO =10mA ~ 500mA
5mV
Short Circuit Current
VIN =15V, @ RL = 0.1Ω
1.3A
Fig.1 Step-Down converter
Fig.2 Step-Down converter with External PNP Saturation Switch
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AMS34063
Application Examples
(Continued)
Line Regulation
VIN = 8V ~16V @ IO =180mA
50mV
Load Regulation
VIN = 12V, @ IO =80mA ~ 180mA
10mV
Fig.3 Step-Up converter
Fig.4 Step-up Converter with External NPN Switch
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Application Examples
AMS34063
(Continued)
Line Regulation
VIN=4.5V~6V @IO=100mA
20mV
Load Regulation
VIN=4.5V~6V @IO=100mA
100mV
Fig.5 lnverting Converter
Fig 6. Voltage lnverting Converter With PNP Saturated Switch
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AMS34063
PACKAGE DESCRIPTION
SOP8 PACKAGE OUTLINE DIMENSIONS
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AMS34063
DIP8 PACKAGE OUTLINE DIMENSIONS
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