9602 Datasheet, PDF (4/8 Pages) National Semiconductor (TI) – Dual Retriggerable, Resettable One Shots

Operating Rules (Continued)
B Use with high inverse leakage current electrolytic ca-
pacitors
The diode in this configuration prevents high inverse
leakage currents through the capacitor by preventing
an inverse voltage across the capacitor The use of
this configuration is not recommended with retriggera-
ble operation
t 0 3 RC_X
TL F 6611–5
C Use to obtain extended pulse widths
This configuration can be used to obtain extended
pulse widths because of the larger timing resistor al-
lowed by beta multiplication Electrolytics with high in-
verse leakage currents can be used
R ^k R_X (0 7) (h_FE Q1) or ^k 2 5 MX whichever is the
lesser
R_X (min) ^k R_Y ^k R_X (max)
(5 kX ^s R_Y ^s 10 kX is recommended)
Q1 NPN silicon transistor with h_FE requirements of
above equations such as 2N5961 or 2N5962
t 0 3 RC_X
7 Input Trigger Pulse Rules (See Triggering Truth Table)
TL F 6611 – 8
Input to Pin 5(11)
(Pin 3(13) e HIGH)
Pin 4(12) e LOW
t₁ t₃ e Min Positive Input Pulse Width ^l 40 ns
t₂ t₄ e Min Negative Input Pulse Width ^l 40 ns
TL F 6611 – 9
Input to Pin 4(12)
(Pin 3(13) e HIGH)
Pin 5(11) e HIGH
8 The retriggerable pulse width is calculated as shown be-
low
 J¹
t_W e t a t_PLH e K R_X C_X
1a
R_X
a t_PLH
TL F 6611–6
This configuration is not recommended with retriggera-
ble operation
5 To obtain variable pulse width by remote trimming the
following circuit is recommended
TL F 6611 – 10
The retrigger pulse width is equal to the pulse width (t) plus a delay time For
pulse widths greater than 500 ns t_W can be approximated as t Retriggering will
not occur if the retrigger pulse comes within 0 3 C_X (ns) after the initial trigger
pulse (i e during the discharge cycle)
9 Reset Operation An overriding clear (active LOW level)
is provided on each one shot By applying a LOW to the
reset any timing cycle can be terminated or any new cy-
cle inhibited until the LOW reset input is removed Trigger
inputs will not produce spikes in the output when the re-
set is held LOW
TL F 6611–7
6 Under any operating condition C_X and R_X (min) must be
kept as close to the circuit as possible to minimize stray
capacitance and reduce noise pickup
TL F 6611 – 11
10 V_CC and Ground wiring should conform to good high
frequency standards so that switching transients on V_CC
and Ground leads do not cause interaction between one
shots Use of a 0 01 to 0 1 mF bypass capacitor be-
tween V_CC and Ground located near the DM9602 is rec-
ommended
For further detailed device characteristics and output performance please
refer to the NSC one-shot application note AN-366
4