AS998 Datasheet, PDF (5/6 Pages) List of Unclassifed Manufacturers – IC intended for use as a PWM controller

PWM Controller
AS998/AS998A
Electrical Characteristics
Electrical Characteristics are guaranteed over full junction temperature range (0 to 105°C). Ambient temperature must be derated
based on power dissipation and package thermal characteristics. Unless otherwise specified, the conditions of test are V_DD = 12 V;
OV = 0V, CSNS = 0V. Cload = 1800pf, Creg = 100 nf (AVVD to GND). To start chip, Vdd must be raised above UVLhigh.
Parameter
Symbol Test Condition
Min.
Typ.
Max. Unit
Startup Current
I_DDO
UVL_HIGH Threshold
64
100
Supply Current
I_DD
No Load
1
2
4
Startup Threshold
UVL_HIGH AS998
9
10
11
UVL off Threshold
Bias Current at POS
Int Regulator Voltage
Oscillator
Parameter
Mean Period
Modulation Repetition Rate
Peak-to-Peak Modulation
Max. Duty Cycle
Error Amplifier
UVL_LOW
V_CLAMP
V_REG
Symbol
T_OSC
T_REP
T_DEV
D_MAX
AS998A
I_DD = 10mA No Load
Y _{IREG = 1mA}
9.5
10
10.5
7.6
8
8.4
13
14
14.7
5.5
6.25
7.0
R Test Condition
Min.
Typ.
Max.
8.4V<V_DD<13.3V; 15 cycle avg. - AS998 7.3
A ^{8.4V<VDD<13.3V; 15 cycle avg. - AS998A 8.1}
9.3
11.7
9.3
10.7
15
Peak-to-Peak change in period
13.7
16.5
23
I ^{N 70}
75
78
Parameter
FB Divider R
M ^VDD ^{Regulation Point}
FB Threshold
I _{Gain (DC)}
Gain-Bandwidth Product
L _{COMP Output High}
COMP Output Low
E ^{COMP Source Current}
COMP Sink Current
Current Sense Comparator
R _Parameter
Scaling of COMP
P^{AC Input Impedance}
Symbol
RFB
VDD_REG
V_REF
AV_OL
GBP
V_COMPH
V_COMPL
I_COMPH
I_COMPL
Test Condition
COMP = FB, V_DD = 12V
No load on COMP
No load on COMP
FB = 2V
FB = 3V
COMP = 3V, FB = 2V
COMP = 1V, FB = 3V
Symbol
R_CSAC
Test Condition
to CSNS input
Fin ≥ FCO
Min.
Typ.
Max.
100
11.4
12
12.6
2.37
2.5
2.62
85
10
4.5
100
250
25
50
100
25
300
500
Min.
Typ.
Max.
0.4
100
Input Filter
F_CS
Time Constant
320
Prop. Delay to Output
tpd1
700
µA
mA
V
V
V
V
V
Unit
µs
µs
cycles
%
%
Unit
kΩ
V
V
dB
MHz
V
mV
µA
µA
Unit
kΩ
ns
ns
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