AMS1073 AMS [Advanced Monolithic Systems Ltd], AMS1073 Datasheet - Page 3

• Manufacturer Part Number: AMS1073
• Description: 1.2A Peak Output Current
• Manufacturer: AMS [Advanced Monolithic Systems Ltd]

ELECTRICAL CHARACTERISTICS
V
Note:
5) Guaranteed by design.
PIN FUNCTIONS
Parameters
Feedback Voltage
Feedback Current
Switch-On Resistance
Switch Leakage
Current Limit
Oscillator Frequency
Fold-back Frequency
Maximum Duty Cycle
Minimum On-Time
Under Voltage Lockout Threshold Rising
Under Voltage Lockout Threshold Hysteresis
EN Input Low Voltage
EN Input High Voltage
EN Input Current
Supply Current (Shutdown)
Supply Current (Quiescent)
Thermal Shutdown
Pin #
IN
1
2
3
4
5
6
= 12V, T
Name Description
GND
BST
SW
EN
FB
IN
A
(5)
= +25°C, unless otherwise noted.
Bootstrap. A capacitor is connected between SW and BS pins to form a floating supply across
the power switch driver. This capacitor is needed to drive the power switch’s gate above the
supply voltage.
Ground. This pin is the voltage reference for the regulated output voltage. For this reason care
must be taken in its layout. This node should be placed outside of the D1 to C1 ground path to
prevent switching current spikes from inducing voltage noise into the part.
Feedback. An external resistor divider from the output to GND, tapped to the FB pin sets the
output voltage. To prevent current limit run away during a short circuit fault condition, the
frequency foldback comparator lowers the oscillator frequency when the FB voltage is below
250mV.
On/Off Control Input. Pull EN above 1.2V to turn the device on. For automatic enable, connect a
100kΩ resistor between this pin and Vin pin.
Supply Voltage.The AMS1073 operates from a + 4.5V to +24V unregulated input.C1 is needed
to prevent large voltage spikes from appearing at the input.
Switch Output.
(5)
(5)
(5)
Advanced Monolithic Systems
Symbol Condition
R
DS(ON)
V
f
t
I
SW
I
ON
I
FB
FB
S
Q
3
http://www.ams-semitech.com
V
V
4.5V ≤ V
V
V
V
V
V
V
V
FB
EN
FB
FB
FB
EN
EN
EN
EN
= 0.8V
= 0.6V
= 0V
= 0.6V
= 0V, V
= 2V
= 0V
= 0V
= 2V, V
IN
≤ 24V
SW
FB
= 1V
= 0V
0.790
Min
1.2
2.5
1.2
AMS1073
0.810
0.35
Typ
460
100
150
150
0.1
1.8
1.4
2.8
2.1
0.1
0.1
0.8
87
0.830
Max
1.7
3.1
0.4
1.0
1.0
10
Units
MHz
kHz
mV
mA
μA
μA
μA
μA
°C
ns
%
V
Ω
A
V
V
V