AMS1076 Datasheet, PDF (3/5 Pages) Advanced Monolithic Systems Ltd – 1A Output Current 0.45Ω Internal Power MOSFET Switch

ELECTRICAL CHARACTERISTICS
V_IN = 12V, T_A = +25°C, unless otherwise noted.
Parameters
Symbol Condition
Feedback Voltage
Feedback Current
Switch-On Resistance
Switch Leakage
V_FB
I_FB
R_DS(ON)
4.5V ≤ V_IN ≤ 18V
V_FB = 0.8V
V_FB = 2V
V_EN = 0V, V_SW = 0V
Current Limit
Oscillator Frequency
f_SW
Fold-back Frequency
V_FB = 0V
Maximum Duty Cycle
V_FB = 0.6V
Minimum On-Time
t_ON
Under Voltage Lockout Threshold Rising
Under Voltage Lockout Threshold Hysteresis
EN Input Low Voltage
En Input High Voltage
EN Input Current
V_EN = 2V
V_EN = 0V
Supply Current (Shutdown)
V_EN = 0V
Supply Current (Quiescent)
V_EN = 2V, V_FB = 1V
Thermal Shutdown
Min
0.790
1.2
2.5
1.2
AMS1076
Typ
0.810
10
2
0.45
1.8
1.4
460
87
100
2.8
150
2.1
0.1
0.1
0.8
Max
0.830
10
1.7
3.1
0.4
Units
V
nA
µA
Ω
μA
A
MHz
KHz
%
ns
V
mV
V
V
μA
1
μA
1
mA
160
°C
PIN FUNCTIONS
Pin #
1
2
3
4
5
6
Name Description
BST
Bootstrap. This capacitor is needed to drive the power switch’s gate above the supply voltage. It
is connected between SW and BS pins to form a floating supply across the power switch driver.
Ground. This pin is the voltage reference for the regulated output voltage. For this reason care
GND 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
FB
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.
EN On/Off Control Input. Pull above 1.2V to turn the device on.
IN
Supply Voltage. The AMS1076 operates from a +4.5V to +18V unregulated input. C1 is needed
to prevent large voltage spikes from appearing at the input.
SW Switch Output.
3
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