CS2844 Datasheet, PDF (4/12 Pages) Cherry Semiconductor Corporation – Current Mode PWM Control Circuit with 50% Max Duty Cycle

CS2844, CS3844, CS2845, CS3845
ELECTRICAL CHARACTERISTICS (continued) (–25° ≤ T_A ≤ 85° for CS2844/2845, 0° ≤ T_A ≤ 70° for CS3844/CS3845.
V_CC = 15 V*; R_T = 10 kΩ, C_T = 3.3 nF for sawtooth mode; unless otherwise stated.)
CS2842A/CS2843A CS3842A/CS3843A
Characteristic
Error Amp Section
Test Conditions
Min Typ Max Min Typ Max
Input Voltage
Input Bias Current
A_VOL
Unity Gain Bandwidth
V_COMP = 2.5 V
V_FB = 0
2.0 ≤ V_OUT ≤ 4.0 V
Note 4.
2.45 2.50 2.55 2.42 2.50 2.58
– –0.3 –1.0 – –0.3 –2.0
65
90
–
65
90
–
0.7 1.0
–
0.7 1.0
–
PSRR
Output Sink Current
Output Source Current
V_OUT High
V_OUT Low
Current Sense Section
12 ≤ V_CC ≤ 25 V
V_FB = 2.7 V, V_COMP = 1.1 V
V_FB = 2.3 V, V_COMP = 5.0 V
V_FB = 2.3 V, R_L = 15 kΩ to GND
V_FB = 2.7 V, R_L = 15 kΩ to V_REF
60
70
–
60
70
–
2.0 6.0
–
2.0 6.0
–
–0.5 –0.8 – –0.5 –0.8 –
5.0 6.0
–
5.0 6.0
–
–
0.7 1.1
–
0.7 1.1
Gain
Notes 5 & 6.
2.85 3.00 3.15 2.85 3.00 3.15
Maximum Input Signal
PSRR
Input Bias Current
Delay to Output
Output Section
V_COMP = 5.0 V. Note 5.
12 ≤ V_CC ≤ 25 V. Note 5.
V_SENSE = 0
T_J = 25°C. Note 4.
0.9 1.0 1.1 0.9 1.0 1.1
–
70
–
–
70
–
–
–2.0 –10
–
–2.0 –10
–
150 300
–
150 300
Output Low Level
I_SINK = 20 mA
I_SINK = 200 mA
–
0.1 0.4
–
0.1 0.4
–
1.5 2.2
–
1.5 2.2
Output High Level
Rise Time
Fall Time
Total Standby Current
I_SOURCE = 20 mA
I_SOURCE = 200 mA
T_J = 25°C, C_L = 1.0 nF. Note 4.
T_J = 25°C, C_L = 1.0 nF. Note 4.
13 13.5 –
12 13.5 –
13 13.5 –
12 13.5 –
–
50 150
–
50 150
–
50 150
–
50 150
Startup Current
–
–
0.5 1.0
–
0.5 1.0
Operating Supply Current
V_CC Zener Voltage
PWM Section
V_FB = V_SENSE = 0 V,
R_T = 10 kΩ, C_T = 3.3 nF
I_CC = 25 mA
–
11
17
–
11
17
–
34
–
–
34
–
Maximum Duty Cycle
–
46
48
50
46
48
50
Minimum Duty Cycle
–
–
–
0
–
–
0
4. These parameters, although guaranteed, are not 100% tested in production.
5. Parameters measured at trip point of latch with V_FB = 0.
6. Gain defined as: A = ∆V_COMP/∆V_SENSE; 0 ≤ V_SENSE ≤ 0.8 V.
*Adjust V_CC above the start threshold before setting at 15 V.
Unit
V
µA
dB
MHz
dB
mA
mA
V
V
V/V
V
dB
µA
ns
V
V
V
V
ns
ns
mA
mA
V
%
%
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