A Novel Programmable Pulse-Broadening Time
Amplifier Controlled by Node Capacitance
Jiangtao Gu, BoWang, ChaoZhang, Tingbing Ouyang, Lizhao Gao
The Key Lab of IMS, School of ECE
Peking University Shenzhen Graduate School, Shenzhen, P.R.China
wangbo@pkusz.edu.cn
Abstract—A novel programmable pulse-broadening time
amplifier (TA) is proposed, which realizes the time-
difference amplification of the rising edge, falling edge
and pulse width of the output clock signal simultaneously.
However, the recently reported TAs only realize either the
time-difference amplification of the signal edge or the signal
pulse width. According to the constant-slope principle, the
transient amplified state and the steady amplified state
exist in the circuit states. As a result, the proposed TA
realizes a fixed time-gain amplification. With the variable-
slope principle, their time gains are linear-programmable
by controlling a 6-bit binary complementary capacitance-
switching matrix simply. Besides, the input pulse-width
range is flexible-adjustable by changing the period of input
clock signal. Under the 0.13um process, the pulse-width
range varies between (-100ps, +100ps) at the center of the
50% duty cycle of the input. The ranges of the time gains
of the output rising edge, output falling edge and the output
pulse are [0.782 12.53], [1.8 13.9], [2.59 26.4]. The variable
ranges of the relative time gain errors of them are [0.16%
3.47%], [0.42% 0.91%], [0.36% 1.89%]. Compared with the
latest TA, its peak-to-peak time gain error of the falling edge
improves much by about 14 times.
Keywords—Complementary capacitance-switching ma-
trix, Constant-slope, Linear-programmable, Pulse-brodening,
Variable-slope, TA, Time gain
I. INTRODUCTION
As the process technology advances, the power supply
voltage scales down and the switching speed of the
transistor increases. The resolution of a digital signal in
time-domain transition is more superior to the analog
signal in voltage-domain transition [1]. While the voltage-
domain amplifier used in the conventional analog-to-
digital converter (ADC) [2] [3] magnifies a small voltage
difference to reach a fine resolution, the TA [4] used in the
time-to-digital (TDC) [5] of the all-digital phase locked
loop (ADPLL) [1] magnifies a small time difference of
clock signal to make it better.
So far, the published TAs are mainly as the following
five kinds of TAs are introduced. The first TA [5] is a
SR-latch positive-feedback structure, but its meta-stability
region causes it to have a narrow input time range and
an inaccurate non-programmable time gain. The second
TA [1] of a cross-couple positive-feedback structure is
a variant of the first meta-stability TA, and it also has
an inaccurate time gain and a narrow input time range.
This research is supported by R&D projects of Shenzhen government
(JCYJ20160229094148396) and NSFC(61471011).
VDD
VSS
Tin
VDD
VSS
V
TH
≈
½ VDD
D0
D0
D0
Tin
VDD
VSS
D1
D1
D
1
Tout1
Tout2
Steady-state output
IN
˖
VCM
˖
OUT
˖
Transition output
After a short period of time
VDD
VSS
CS
˖
Steady-state output
Pulse-broadening
TA
D0
OUT
D0
IN
D1
D1
Tout1
Tout2
Tout=
Tout1
+
Tout2
=G1*
Tin+T
os1
+ G2*
Tin+T
os2
=
G*
Tin+T
os
Co
CL
OUT
VCM
(a)
(b)
(c)
Tout=
Tout1+
Tout2
=G1*
Tin+T
os1
+ G2*
Tin+T
os2
=G*
Tin+T
os
Tin
IN
Fig. 1: The pulse-broadening TA: (a) Concept diagram (b) Basic
schematic (c) Timing diagram
The third TA [6] consists of two cross-couple reverse-
transmission chains of the delay cells with different unit
delays, but its time gain is fixed. The fourth TA [4]
exploits the OR gate to add the pulse for a time amplifica-
tion. Although the fourth TA has a wide input pulse-width
range and an accurate time gain, its application is special.
The fifth TA [7] adopts a differential symmetric structure
and regulates the bias current to realize time-different
amplification, Its input time range reaches nanosecond
magnitude and the time gain can be programmed, but
the circuit implementation is more complex due to the
compactors and the current sources. Generally, the above
TAs only realize the time-difference amplification of the
single edge or the fourth TA only adds the pulse width.
In this paper, the key parts of the proposed TA
consist of a charge inverter, an initial capacitor, a PMOS-
NMOS complementary capacitance-switching matrix and
two shaping inverters. The time-difference amplification
of the rising edge, falling edge and pulse width of the
output can be reached simultaneously. Controlling the
capacitance-switching matrix and adopting the related
improvements can linearly program the time gains easily.
The simulation results in Section IV demonstrate its peak-
to-peak time gain error of the falling edge decreases
much by about 14 times compared with the latest reported
TA. Moreover, its input pulse-width range varies between
more than (±100ps) by changing the period of input clock
flexibly.