參數(shù)資料
型號(hào): MAX132
廠商: Maxim Integrated Products, Inc.
英文描述: 18-Bit ADC with Serial Interface(±18-BIT,單通道,具有串行接口的ADC)
中文描述: ±18位ADC,串行接口
文件頁(yè)數(shù): 9/16頁(yè)
文件大小: 168K
代理商: MAX132
M
±18-Bit ADC with S erial Interfac e
_______________________________________________________________________________________
9
Note:
Capacitor values are for a 3.0V integrator swing.
Manufactures of miniature quartz resonators include:
Epson of America
C-2 (through-hole), MC-306 (SMD)
Phone: (310) 787-6300; Fax: (310) 782-5320
Integrator Resistor
The integrator resistor sets the maximum integrator out-
put current for the integrate phase. A 602k
low-noise,
metal-film integrator resistor is recommended for use
with reference voltages between 545mV and 655mV.
Best linearity is achieved when the integration current
(I
INT
) does not exceed 2.5μA. For other reference volt-
ages, select R
INT
as follows:
Integrator Capacitor
The oscillator frequency, integrator resistor, and inte-
grator capacitor set the maximum integrator output volt-
age swing for full-scale reading. The integrator voltage
swing is about 3V and should not come within 2V of
either supply rail to avoid saturation. A 602k
integrator
resistor and a 4.7nF integrator capacitor are recom-
mended with a clock frequency of 32,768Hz. If different
clock frequencies are used, select C
INT
using the fol-
lowing equations:
The integrator capacitor’s dielectric absorption directly
affects integral nonlinearity. High-quality metal-film
capacitors are recommended in the following order of
preference: polypropylene, polystyrene, polycarbon-
ate, and polyester (Mylar). The polyester capacitor will
generate some integral nonlinearity.
To minimize noise, INT OUT should drive the outside
foil (negative end) of the capacitor. Manufacturers of
polypropylene capacitors include Sprague (715P),
Panasonic (ECQ-P), Roderstein (KP1835), Wima (FKP),
and CSF Thompson (PL/PS).
Reference Capacitor
The reference capacitor must be small enough to fully
charge from a discharged state on power-up in reason-
able time, and large enough so the charge does not
droop excessively during a conversion. The reference
capacitor is normally 0.1μF for all oscillator frequencies.
For applications that require a physically smaller capaci-
tor, the equation below will maintain C
REF
proportionality:
The reference capacitor must have low leakage, since
it stores the reference voltage while floating during the
deintegrate phase. Any leakage or charge loss during
this phase changes the scale factor and will cause an
error. Appropriate metal-film capacitors recommended
for their low-leakage characteristics
1
are (in this order):
polypropylene (up to +105°C, large size), teflon (suit-
able for use up to +125°C, large size), polystyrene,
polycarbonate, and polyester.
At temperatures above +85°C, capacitor leakage may
affect accuracy. In such cases, increasing the value of
C
REF
up to 50% and more will help at the expense of
longer start-up time at power-on. The start-up time is
proportional to C
REF
and can be estimated by:
Table 1. Crystal Frequencies and
Integrator Capacitors for 50Hz to 60Hz
Operation
Conv/sec
16
32
48
64
80
96
Crystal
Freq.
(Hz)
32,768
65,536
98, 304
131,072
163,840
196,608
C
INT
/60Hz
(pF)
4700
2700
1800
1200
1000
820
C
INT
/50Hz
(pF)
6800
3300
2000
1500
1200
1000
Resistor
(k
)
602
602
602
602
602
602
R
V
I
INT
A
A
and
I
V
R
INT
REF
INT
REF
INT
.
0 5
=
<
<
=
2 5
μ
μ
t
f
for
Hz
e
or
t
f
for
Hz
e
INT
OSC
INT
OSC
,
mod
,
mod
=
=
545
60
655
50
C
f
REF
OSC
.
=
0 0033
t
C
F
x
x
k
START UP
REF
=
(
)
μ
10
100
1
Pease, R.A., “Understanding Capacitor Soakage to Optimize
Analog Systems,” EDN October 13, 1982, p.125.
C
V
t
R
(
V
where
V
V
V
and
INT
IN FS
(
INT
INT
SWING
SWING
(
) (
)
) (
),
.
;
)
=
<
<
1
3 5
相關(guān)PDF資料
PDF描述
MAX133 3 3/4 Digital ADC(3 3/4 位數(shù)字ADC)
MAX139 3 1/2 Digital ADC(3 1/2位數(shù),具有能隙基準(zhǔn)源ADC)
MAX1479 300MHz to 450MHz Low-Power, Crystal-Based +10dBm ASK/FSK Transmitter
MAX1479ATE 300MHz to 450MHz Low-Power, Crystal-Based +10dBm ASK/FSK Transmitter
MAX1480A Complete, Isolated RS-485/RS-422 Data Interface(半雙工,完全隔離的RS-485/422收發(fā)器)
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
MAX13202EALT+ 制造商:Maxim Integrated Products 功能描述: 制造商:Maxim Integrated Products 功能描述:ESD PROTECTORS 6PIN UDFN - Rail/Tube
MAX13202EALT+T 功能描述:TVS二極管陣列 2Ch ESD Protection Diode Array RoHS:否 制造商:Littelfuse 極性: 通道:4 Channels 擊穿電壓: 鉗位電壓:11.5 V 工作電壓:2.5 V 峰值浪涌電流:20 A 安裝風(fēng)格:SMD/SMT 端接類(lèi)型:SMD/SMT 系列: 最小工作溫度:- 40 C 最大工作溫度:+ 85 C
MAX13204EALT 制造商:Maxim Integrated Products 功能描述:LOW-CAPACITANCE 4-/6-/8-CHANNEL + - Rail/Tube
MAX13204EALT+ 制造商:Maxim Integrated Products 功能描述: 制造商:Rochester Electronics LLC 功能描述:
MAX13204EALT+T 功能描述:TVS二極管陣列 4Ch ESD Protection Diode Array RoHS:否 制造商:Littelfuse 極性: 通道:4 Channels 擊穿電壓: 鉗位電壓:11.5 V 工作電壓:2.5 V 峰值浪涌電流:20 A 安裝風(fēng)格:SMD/SMT 端接類(lèi)型:SMD/SMT 系列: 最小工作溫度:- 40 C 最大工作溫度:+ 85 C