CS4121 Datasheet, PDF (6/8 Pages) Cherry Semiconductor Corporation – Low Voltage Precision Air-Core Low Voltage Precision Air-Core

Circuit Description and Application Notes: continued
V_REG
FREQ_IN
R3
V_C(t)
+Ð
SQ_OUT
C_T R4
+
Ð
Q_SQUARE
2.0V
0.25V
CP+
Q1
2.0V
Q3 ^CPÐ
Q2
+
Ð
R_T
F/V_OUT
F to V
C4
Figure 5A: Partial Schematic of Input and Charge Pump
PW
V_CC
FREQ_IN ⁰
SQ_OUT
0
V_REG
I_CP+
V_CP+
0
T
T-PW
Figure 5B: Timing Diagram of FREQ_IN and I_CP
6