Datasheet

Functional description ST7538Q
28/44
Voltage control loop formula
Note: The rate of R2 takes in account the input resistance on the SENSE pin (36 K
Ω ).
5.6nF capacitor effect has been neglected.
Figure 15. Typical output current vs rcl
Table 10. Vout vs R1 & R2 resistors value
Vout (Vrms) Vout (dBµV) (R1+R2)/R2 R2 (KΩ) R1 (KΩ)
0.150 103.5 1.1 7.5 1.0
0.250 108.0 1.9 5.1 3.9
0.350 110.9 2.7 3.6 5.6
0.500 114.0 3.7 3.3 8.2
0.625 115.9 4.7 3.3 11.0
0.750 117.5 5.8 2.7 12.0
0.875 118.8 6.6 2.0 11.0
1.000 120.0 7.6 1.6 10.0
1.250 121.9 9.5 1.6 13.0
1.500 123.5 10.8 1.6 15.0
VR
PK
R
1
R
2
+
R
2
--------------------
VCL
TH
VCL
HYST
±()⋅≅
100
125
150
175
200
225
250
275
300
325
Irms
(mA)
2 2.5 3 3.5
Rcl(KΩ)
D01IN1311
4 4.5 5