DS1073 [MAXIM]
3V EconOscillator/Divider;
| 型号： | DS1073 |
| 厂家： | 
MAXIM INTEGRATED PRODUCTS |
| 描述： | 3V EconOscillator/Divider |
| 文件： | 总18页 (文件大小：266K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
DS1073
www.maxim-ic.com
FEATURES
PIN ASSIGNMENT
C Dual fixed-frequency outputs (30kHz to
100MHz)
1
8
OSCIN
XTAL
I/O
C User-programmable on-chip dividers (from 1
to 513)
2
7
OUT0
VCC
3
4
6
5
OE
C User-programmable on-chip prescaler (1, 2,
4)
PDN/SELX
GND
C No external components
C M0.5% initial tolerance (commercial)
C M1% variation over commercial temperature
and voltage
DS1073Z-XXX 150-mil SOIC
DS1073M-XXX 300-mil DIP
XXX = Frequency option
C Internal clock, external clock or crystal
reference options
FREQUENCY OPTIONS
Part No.
Max O/P Freq.
C 2.7 to 3.6V supply
DS1073M/Z-100
DS1073M/Z-80
DS1073M/Z-66
DS1073M/Z-60
100.000MHz
80.000MHz
66.667MHz
60.000MHz
C Power-down mode
C Synchronous output gating
C Industrial temp operation with relaxed
specifications
DESCRIPTION
The DS1073 is a fixed-frequency oscillator requiring no external components for operation. Numerous
operating frequencies are possible in the range of approximately 27.3kHz to 100MHz through the use of
an on-chip programmable prescaler and divider.
The DS1073 features a master oscillator followed by a prescaler and then a programmable divider. The
prescaler and programmable divider are user-programmable with the desired values being stored in non-
volatile memory. This allows the user to buy an off the shelf component and program it on site prior to
board production. Design changes can be accommodated on the fly by simply programming different
values into the device (or reprogramming previously programmed devices).
The DS1073 is shipped from the factory configured for half the maximum operating frequency. Contact
the factory for specially programmed devices. As alternatives to the onboard oscillator an external clock
signal or a crystal may be used as a reference. The choice of reference source (internal or external) is
user-selectable at the time of programming (or on the fly if the SEL mode is chosen).
The DS1073 features a dual-purpose I/O pin. If the device is powered up in Program mode this pin can be
used to input serial data to the on chip registers. After a Write command this data is stored in non-volatile
memory. When the chip is subsequently powered up in operating mode these values are automatically
restored to the on-chip registers and the I/O pin becomes the oscillator output.
The DS1073 may be operated over either the commercial (TA = 0C to 70C) or industrial (TA = -40C to +
85C) temperature ranges. AC and DC Electrical Characteristics Tables for operation in both these
temperature ranges are given at the end of the data sheet.
1 of 18
090503
DS1073
The DS1073 is available in 8-pin DIP or SOIC packages, allowing the generation of a clock signal easily,
economically and using minimal board area.
BLOCK DIAGRAM Figure 1
PART
NO.
INTOSC
FREQUENCY
SUFFIX
-100
-80
100.000 MHz
80.000 MHz
66.667 MHz
60.000 MHz
-66
-60
2 of 18
DS1073
PIN DESCRIPTIONS
IN/OUT Pin (I/O): This pin is the main oscillator output, with a frequency determined by clock
reference, M and N dividers. Except in programming mode this pin is always an output. In programming
mode this pin is an input and output.
External Oscillator Input (OSCIN): This pin can be used to supply an external reference frequency to
the device.
Crystal Oscillator Connection (XTAL): A crystal can be connected between this pin and OSCIN to
provide an alternative frequency reference. The crystal must be used in fundamental mode. If a crystal is
not used this pin should be left open.
Output Enable Function (OE pin): The DS1073 also features a “synchronous” output enable. When
OE is at a high logic level the oscillator free runs. When this pin is taken low OUT is held low,
immediately if OUT is already low, or at its next high-to-low transition if OUT is high. This prevents any
possible truncation of the output pulse width when the enable is used. While the output is disabled the
master oscillator continues to run (producing an output at OUT0, if the EN0 bit = 0) but the internal
counters (/N) are reset. This results in a constant phase relationship between OE’s return to a high level
and the resulting OUT signal. When the enable is released OUT will make its first transition within one
to two clock periods of the master clock.
Power-Down/Select Function ( PDN /SELX pin): The Power-Down/Select ( PDN /SELX ) pin has a user-
selectable function determined by one bit (PDN bit) of the user-programmable memory. According to
which function is selected, this pin will be referred to as PDN or SELX .
If the Power-Down function is selected (PDN bit = 1) a low logic level on this pin can be used to make
the device stop oscillating (active low) and go into a reduced power consumption state. The “Enabling
Sequencer” circuitry will first disable OUT in the same way as when OE is used. Next OUT0 will be
disabled in a similar fashion. Finally the oscillator circuitry will be disabled. In this mode both outputs
will go into a high-impedance state.
The power consumption in the power-down state is much less than if OE is used because the internal
oscillator (if used) is completely powered down. Even if an external reference or a crystal is used all of
the on-chip buffers are powered down to minimize current drain. Consequently the device will take
considerably longer to recover (i.e., achieve stable oscillation) from a power-down condition than if the
OE is used.
If the Select function is chosen (PDN bit = 0) this pin can be used to switch between the internal
oscillator and an external reference (or crystal) on the fly. When this mode is chosen the E/I select bit is
overridden, a high logic level on SELX will select the internal oscillator, a low logic level will select the
external reference (or crystal oscillator).
Reference Output (OUT0 pin): A reference output, OUT0, is also available from the output of the
reference select mux. This output is especially useful as a buffered output of a crystal defined master
frequency. OUT0 is unaffected by the OE pin, but is disabled in a glitchless fashion if the device is
powered down. If this output is not required it can be permanently disabled by setting the EN0 bit to 1,
and there will be a corresponding reduction in overall power consumption.
3 of 18
DS1073
USER-PROGRAMMABLE REGISTERS
The following registers can be programmed by the user to determine operating frequency and mode of
operation. Details of how these registers are programmed can be found in a later section, in this section
the function of the registers are described. The register settings are non-volatile, the values being stored
automatically in EEPROM when the registers are programmed. Note: The register bits cannot be used to
make mode or frequency changes on the fly. Changes can only be made by powering the device up in
“Programming” mode. For them to be become effective the device must then be powered down and
powered up again in “Operation” mode.
For programming purposes the register bits are divided into two 9-bit words: the MUX word determines
mode of operation and prescaler values; the DIV word sets the value of the programmable divider.
MUX WORD Figure 2
(MSB)
(LSB)
E/ I
0*
0*
0*
PDN
M
DIV1
EN0
MSEL
*These bits must be set to 0
I
E/
This bit selects either the internal oscillator or the external/ crystal reference.
1 = External/Crystal
0 = Internal Oscillator
however, if the PDN bit is set to 0 the E/I bit will be overridden by the logic level on the PDN /SELX pin.
Table 1
( PDN / SELX
PDN
I
BIT
0
E/
PIN
OSCILLATOR MODE
X
0
EXTERNAL/CRYSTAL
0
X
X
0
1
INTERNAL
1
0
POWER-DOWN
INTERNAL
1
1
1
1
1
EXTERNAL/CRYSTAL
DIV1
This bit allows the master clock to be routed directly to the output (DIV1 = 1). The N programmable
divider is bypassed so the programmed value of N is ignored. The frequency of the output (fOUT) will be
INTCLK or EXTCLK depending on which reference has been selected. If the Internal clock is selected
the M prescaler may still be used, so in this case fOUT = INTOSC/M (which also equals MCLK and
INTCLK). If DIV1 = 0 the programmable divider functions normally.
MSEL
This bit determines whether or not the M prescaler is bypassed. MSEL = 1 will bypass the prescaler.
MSEL = 0 will switch in the prescaler, with a divide-by number determined by the M bit.
M
This bit sets the divide-by number for the prescaler. M = 0 results in divide-by-4, M = 1 results in divide-
by-2. The setting of this bit is irrelevant if MSEL = 1.
4 of 18
DS1073
Table 2
I
MSEL
DIV1
E/
M
BIT
0
BIT
0
BIT*
BIT
OPERATION
0
0
0
1
0
0
0
1
0
INTERNAL OSCILLATOR DIVIDED BY 4*N
INTERNAL OSCILLATOR DIVIDED BY 2*N
INTERNAL OSCILLATOR DIVIDED BY N
EXTERNAL OSCILLATOR DIVIDED BY N
INTERNAL OSCILLATOR DIVIDED BY 1
INTERNAL OSCILLATOR DIVIDED BY 4
INTERNAL OSCILLATOR DIVIDED BY 2
EXTERNAL OSCILLATOR DIVIDED BY 1
0
0
1
0
1
X
0
X
1
X
1
X
1
0
0
1
0
1
1
X
X
*Assuming PDN bit = 1, otherwise internal/external selection will be controlled by the PDN /SELX pin.
DIV WORD Figure 3
(MSB)
(LSB)
N (9-BITS)
PDN
This bit is used to determine the function of the PDN /SELX pin. If PDN = 0, the PDN /SELX pin can be
used to determine the timing reference (either the internal oscillator or an external reference/crystal). If
PDN = 1, the PDN /SELX pin is used to put the device into power-down mode.
EN0
This bit is used to determine whether the OUT0 pin is active or not. If EN0 = 1, OUT0 is disabled (High-
impedance). If EN0 = 0, the internal reference clock (MCLK) is output from OUT0. The OE pin has no
effect on OUT0, but OUT0 is disabled as part of the power-down sequence.
N
These nine bits determine the value of the programmable divider. The range of divisor values is from 2 to
513, and is equal to the programmed value of N plus 2:
Table 3
BIT
DIVISOR (N)
VALUES
VALUE
000000000
2
000000001
3
.
.
.
.
.
.
.
.
.
.
111111111
513
NOTE:
The maximum value of N is constrained by the minimum output frequency. If the internal clock is
selected, INTOSC/(M*N) must be greater than fOUTmin; if the external clock is selected, EXTCLK/N must
be greater than fOUTmin. (If DIV1 = 1, then INTOSC or EXTCLK, as applicable, must exceed fOUTmin).
5 of 18
DS1073
OPERATION OF OUTPUT ENABLE
Since the output enable, internal master oscillator and/or external master oscillator are likely all
asynchronous there is the possibility of timing difficulties in the application. To minimize these
difficulties the DS1073 features an “enabling sequencer” to produce predictable results when the device is
enabled and disabled. In particular the output gating is configured so that truncated output pulses can
never be produced.
ENABLE TIMING
The output enable function is produced by sampling the OE input with the output from the prescaler mux
(MCLK) and gating this with the output from the programmable divider. The exact behavior of the
device is therefore dependent on the setup time (tSU) from a transition on the OE input to the rising edge
of MCLK. If the actual setup time is less than tSUEM, then one more complete cycle of MCLK will be
required to complete the enable or disable operation (see diagrams). This is unlikely to be of any
consequence in most applications, and then only if the value for N is small. In general, the output will
make its first positive transition between approximately one and two clock periods of MCLK after the
rising edge of OE.
Figure 4
tM = PERIOD OF MCLK
td = PROP DELAY FROM MCLK I TO OUT I
MAX VALUE OF ten = tSUEM + 2 tM + td
MIN VALUE OF ten = tSUEM + tM + td
DISABLE TIMING
If OE goes low while OUT is high, the output will be disabled on the completion of the output pulse. If
OUT is low, the disabling behavior will be dependent on the setup time between the falling edge of OE
and the rising edge of MCLK. If tSU < tSUEM the result will be one additional pulse appearing on the
output before disabling occurs.
If the device is in divide-by-one mode, the disabling occurs slightly differently. In this case if tSU > tSUEM
one additional output pulse will appear, if tSU < tSUEM then two additional output pulses will appear.
The following diagrams illustrate the timing in each of these cases.
Figure 5
tM = PERIOD OF MCLK
td = PROP DELAY FROM MCLK I TO OUT I
tOUTH = WIDTH OF OUTPUT PULSE
MAX VALUE OF tdis = tSUEM + td + tOUTH
MIN VALUE OF tdis = 0
6 of 18
DS1073
Figure 6
tM = PERIOD OF MCLK
td = PROP DELAY FROM MCLK I TO OUT I
tOUTH = WIDTH OF OUTPUT PULSE
MAX VALUE OF tdis = tSUEM + td + tOUTH + tM
MIN VALUE OF tdis = tSUEM + td + tOUTH
SELECT TIMING
If the PDN bit is set to 0, the PDN /SELX pin can be used to switch between the internal oscillator and an
externalor crystal reference. The “Enabling Sequencer” is again employed to ensure this transition occurs
in a glitch-free fashion. Two asynchronous clock signals are involved, INTCLK is the internal reference
oscillator divided by one or whatever value of M is selected. EXTCLK is the clock signal fed into the
OSCIN pin, or the clock resulting from a crystal connected between OSCIN and XTAL. The behavior of
OUT0 is described in the following paragraphs, the OUT pin will behavior similarly but will be divided
by N.
FROM INTERNAL TO EXTERNAL CLOCK
This is accomplished by a high to low transition on the SELX pin. This transition is detected on the
falling edge of INTCLK. The output OUT0 will be held low for a minimum of half the period of
INTCLK (tI/2), then if EXTCLK is low it will be routed through to OUT0. If EXTCLK is high the
switching will not occur until EXTCLK returns to a low level.
Figure 7
Depending on the relative timing of the SELX signal and the internal clock, there may be up to one full
cycle of tI on the output after the falling edge of SELX . Then, the “low” time (tLOW) between output
pulses will be dependent on the relative timing between tI and tE. The time interval between the falling
edge of SELX and the first rising edge of the externally derived clock is tSIE. Approximate maximum and
minimum values of these parameters are:
tLOW (min) = tI/2
tLOW (max) = tI/2 + tE
tSIE (min) = tI/2
t
SIE (max) = 3tI/2 + tE
NOTE:
In each case there will be a small additional delay due to internal propagation delays.
7 of 18
DS1073
FROM EXTERNAL TO INTERNAL CLOCK
This is accomplished by a low to high transition on the SELX pin. In this case the switch is level
triggered, to allow for the possibility of a clock signal not being present at OSCIN. Note therefore, that if
a constant high-level signal is applied to OSCIN it will not be possible to switch over to the internal
reference. (Level triggering was not employed for the switch from internal to external reference as this
approach is slower and the internal clock may be running at a much higher frequency than the maximum
allowed external clock rate). When SELX is high and a low level is sensed on EXTCLK, OUT0 will be
held low until a falling edge occurs on INTCLK, then the next rising edge of INTCLK will be routed
through to OUT0.
Figure 8
Depending on the relative timing of the SELX signal and the external clock, there may be up to one full
tEhigh period on the output after the rising edge of SELX . Then, the “low” time (tLOW) between output
pulses will be dependent on the relative timing between tI and tE. The time interval between the falling
edge of SELX and the first rising edge of the externally derived clock is tSIE. Approximate maximum and
minimum values of these parameters are:
tLOW (min) = tI/2
t
LOW (max) = 3tI/2 + tElow
tSIE (min) = tI/2
SIE (max) = 3tI/2 + tEhigh
t
NOTE:
In each case there will be a small additional delay due to internal propagation delays.
POWER-DOWN CONTROL
If the PDN bit is set to 1, the PDN /SELX pin can be used to power-down the device. If PDN is high the
device will run normally.
POWER-DOWN
If PDN is taken low a power-down sequence is initiated. The “Enabling Sequencer” is used to execute
events in the following sequence:
1. Disable OUT (same sequence as when OE is used) and reset N counters.
2. When OUT is low, switch OUT to high-impedance state.
3. Disable MCLK (and OUT0 if EN0 bit = 0), switch OUT0 to high impedance state.
4. Disable internal oscillator and OSCIN buffer.
8 of 18
DS1073
POWER-UP
When PDN is taken to a high level the following power-up sequence occurs:
1. Enable internal oscillator and/or OSCIN buffer.
2. Set M and N to maximum values.
3. Wait approximately 256 cycles of MCLK for it to stabilize.
4. Reset M and N to programmed values.
5. Enable OUT0 (assuming EN0 bit = 0).
6. Enable OUT.
Steps 2 through 4 exist to allow the oscillator to stabilize before enabling the outputs.
Figure 9
POWER-ON RESET
When power is initially applied to the device supply pin, a power-on reset sequence is executed, similar
to that which occurs when the device is restored from a power-down condition. This sequence comprises
two stages, first a conventional POR to initialize all on-chip circuitry, followed by a stabilization period
to allow the oscillator to reach a stable frequency before enabling the outputs:
1. Initialize internal circuitry.
2. Enable internal oscillator and/or OSCIN buffer.
3. Set M and N to maximum values.
4. Wait approximately 256 cycles of MCLK for the oscillator to stabilize.
5. Load M and N programmed values from EEPROM.
6. Enable OUT0 (assuming EN0 = 0).
7. Enable OUT.
9 of 18
DS1073
Figure 10
PROGRAMMING
Normally when power is applied to the supply voltage pin the device will enter its normal operating mode
following the power-on reset sequence. However the device can be made to enter a programming mode if
a pullup resistor is connected between I/O and the supply voltage pin, prior to power-up. The method
ꢀ
used for programming is a variant of the 1-Wire protocol used on a number of Dallas Semiconductor
products.
HARDWARE
The hardware configuration is shown in the diagram. A bus master is used to read and write data to the
DS1073’s internal registers. The bus master may have either an open drain or TTL-type architecture.
Figure 11
Programming mode is entered by simply powering up the DS1073 with a pullup of approximately 5kꢀ.
This will pull the I/O pin above VIH on power-up and initiate the programming mode, causing the
DS1073 to internally release the I/O pin (after tPOR), and allow the pullup resistor to pull the pin to the
supply rail and await the Master Tx Reset pulse (see diagram).
10 of 18
DS1073
NOTE:
To ensure normal operation any external pullup applied to I/O must be greater than 20kꢀꢁin value.
This will cause the I/O pin to remain below VIH on power-up, resulting in normal operation at the end of
tSTAB
.
Figure 12
VCC
TRANSACTION SEQUENCE
The sequence for accessing the DS1073 via the 1-Wire port is as follows:
Initialization
Function Command
Transaction/Data
INITIALIZATION
All transactions on the 1-Wire bus begin with an initialization sequence. The initialization sequence
consists of a reset pulse transmitted by the bus master followed by a presence pulse(s) transmitted by the
DS1073. The presence pulse lets the bus master know that the DS1073 is present and is ready to operate.
Figure 13
FUNCTION COMMANDS
Once the bus master has detected a presence, it can issue one of the four function commands. All
function commands are 8 bits long, and are written lsb first. A list of these commands follows:
Write DIV Register [01H]
This command allows the bus master to write to the DS1073’s DIV register.
11 of 18
DS1073
Read DIV Register [A1H]
This command allows the bus master to read the DS1073’s DIV register.
Write MUX Register [02H]
This command allows the bus master to write to the DS1073’s MUX register.
Read MUX Register [A2H]
This command allows the bus master to read the DS1073’s MUX register.
TRANSACTION/DATA
Immediately following the Function Command, the 9 data bits are written to or read from the DS1073.
This data is written/read lsb first. The following diagrams illustrate the timing. Once data transfer is
complete, a new transaction sequence can be started by re-initializing the device. Therefore to program
both the DIV and MUX registers two complete transaction sequences are required.
READ/WRITE TIME SLOTS
The definitions of write and read time slots are illustrated below. All time slots are initiated by the master
driving the data line low. The falling edge of the data line synchronizes the DS1073 to the master by
triggering a delay circuit in the DS1073. During write time slots, the delay circuit determines when the
DS1073 will sample the data line. For a read data time slot, if a 0 is to be transmitted, the delay circuit
determines how long the DS1073 will hold the data line low overriding the 1 generated by the master. If
the data bit is a 1, the DS1073 will leave the read data time slot unchanged.
WRITE 1 TIME SLOT Figure 14
WRITE 0 TIME SLOT Figure 15
12 of 18
DS1073
READ DATA TIME SLOT Figure 16
RETURN TO NORMAL OPERATION
When programming is complete the DS1073 should be powered down. If the pullup resistor on the I/O
pin is removed, normal device operation will be restored next time power is applied.
DEFAULT REGISTER VALUES
Unless ordered from the factory with specific register program values, the DS1073 is shipped with the
following default register values:
DIV = 0 0000 0000 (Programmable divider will divide by two)
MUX = 0 0011 0100
OUT0 Disabled
Power-Down Enabled, Select Disabled
M = 4 (Ignored, see MSEL )
MSEL = 1 (M prescaler bypassed)
DIV1 = 0 (N Dividers enabled)
E/I = 0 (Internal oscillator selected)
13 of 18
DS1073
ABSOLUTE MAXIMUM RATINGS*
Voltage on Any Pin Relative to Ground
Operating Temperature
-1.0V to +7.0V
0LC to 70LC
-55LC to +125LC
See J ꢂ STD-020A
Storage Temperature
Soldering Temperature
* This is a stress rating only and functional operation of the device at these or any other conditions above
those indicated in the operation sections of this specification is not implied. Exposure to absolute
maximum rating conditions for extended periods of time may affect reliability.
DC ELECTRICAL CHARACTERISTICS
(TA = 0°C to +70°C) (VCC =2.7V to 3.6V)
PARAMETER
SYMBOL CONDITION MIN TYP MAX UNITS NOTE
Supply Voltage
VCC
2.7
3.6
0.4
0.8
V
High-level Output Voltage
(I/O, OUT0)
VOH
IOH = -2mA,
2.4
V
V
CC = MIN
Low-level Output Voltage
(I/O, OUT0)
VOL
IOL = 2mA
V
High-level Input Voltage
Low-level Input Voltage
High-level Input Current
VIH
VIL
2
V
V
VIH = 2.4V, VCC
= 3.6V
VIH = VCC =3.6V
IIH
IIH
1
10
uA
uA
(PDN /SELX , OE)
(OSCIN)
Low-level Input
IIL
IIL
-1
uA
uA
Current( PDN /SELX , OE)
VIL=0,VCC=3.6V
VIL=0,VCC=3.6V
-10
(OSCIN)
Supply Current (Active)
DS1073-100
ICC
CL = 15 pF
25
40
mA
DS1073-80
(both outputs)
DS1073-66
DS1073-60
Standby Current
(power-down)
ICCQ
Power-Down
Mode
0.8
uA
14 of 18
DS1073
AC ELECTRICAL CHARACTERISTICS (TA = 0°C to +70°C) (VCC =2.7V to 3.6V)
PARAMETER
Output Frequency
Accuracy
SYMBOL CONDITION MIN TYP MAX UNITS NOTES
VCC = 3.15V,
fO
-0.5
0
+0.5
%
TA = 25LC
Over temp and
voltage
Combined Frequency
Variation
-1
+1
%
ꢃfO’
Long Term Stability
-0.5
+0.5
50
%
MHz
1
2
ꢃfO”ꢁ
T = 25LC
External clock
Crystal
Maximum Input
Frequency
fOSCIN
25
MHz
reference
Minimum Output
Frequency
Power-Up Time
Enable OUT from PDN ↑
Enable OUT0 from PDN ↑
I/O Hi-Z from PDN ↓
fOUT
29.3
kHz
3
tPOR + tSTB
tSTABb
tSTAB
0.1
0.1
0.1
1
1
1
1
1
ms
ms
ms
ms
ms
4, 5
5
5, 6
tPDN
tPDN
OUT0 Hi-Z from PDN ↓
Load Capacitance
(I/O, OUT0)
Output Duty Cycle
I/O
CL
15
pF
7
8
40
40
60
60
%
%
OUT0
Jitter
J
100
pS
NOTES:
1. Additive to ꢃfO’.
2. This is the maximum frequency which can be applied to OSCIN, or, the maximum crystal frequency
that can be used. If a crystal is used it must be operated in fundamental mode.
3. The values of M, N and the frequency of OSCIN (if used) must be chosen so that this spec is met.
4. This is the time from when VCC is applied until the output starts oscillating.
5. When the device is initially powered up, or restored from the power-down mode, OE should be
asserted (high). Otherwise the start of the tSTAB interval will be delayed until OE goes high. OE can
subsequently be returned to a low level during the tSTAB interval to force out low after the tSTAB
,
interval. If the external mode is selected tSTAB will be a function of the OSCIN period, i.e., external
clock frequency. See “Calculated Parameters” to determine the value of tSTAB in this case.
6. Although OE does not normally affect OUT0 operation, if OE is held low during power-up the start of
the tSTAB period will be delayed until OE is asserted. If OE remains low, OUT0 will not start.
7. Operation with higher capacitive loads is possible but may impair output voltage swing and maximum
operation frequency.
8. Parameter given is 3 sigma.
15 of 18
DS1073
AC ELECTRICAL CHARACTERISTICS – CALCULATED PARAMETERS
The following characteristics are derived from various device-operating parameters (frequency, mode,
etc.). They are not specifically tested or guaranteed and may differ from the min and max limits shown by
a small amount due to internal device setup times and propagation delays. However, the equations in the
max column can be used to estimate a more accurate idea of typical device performance than the
guaranteed values.
PARAMETER
I/O ↑ from OE ↑
I/O ↓ from OE ↓
N = 1
SYMBOL CONDITION
MIN
tM
MAX
2tM
tEN
tDIS
tDIS
tOUTH
0
tOUTH + tM
tOUTH
N ≥ 2
tSIE
tSEI
tI/2
tI/2
3tI/2 + tE
SELX ↓ to OUT0 ↑
3tI/2 + tEhigh
-Internal to External
-External to Internal
Break during SEL switch
-Internal to External
tLOW
tLOW
tI/2
tI/2
tI/2 + tE
3tI/2 + tElow
-External to Internal
tPDN
tPDN
tOUTH
0
tOUTH + tM
tOUTH
PDN ↓ to I/O Hi-Z
N = 1
N ≥ꢁ2
tPDN
tPDN
tOUTH
0
tOUTH + tM
tOUTH
PDN ↓ to OUT0 Hi-Z
N = 1
N ≥ꢁ2
tSTAB
tSTAB
256tM
256tM
256tM
256tM
PDN ↑ to I/O ↑
PDN ↑ to OUT0 ↑
I/O ↑ after Power-up
OUT0 ↑ after Power-up
16 of 18
DS1073
DC ELECTRICAL CHARACTERISTICS
(TA = -40°C to +85°C) (VCC = 2.7V to 3.6V)
PARAMETER
SYMBOL CONDITION MIN TYP MAX UNITS NOTES
Supply Voltage
VCC
2.7
2.4
3.6
V
V
High-level Output
Voltage
VOH
IOH = -2 mA,
VCC = MIN
(I/O, OUT0)
Low-level Output Voltage
(I/O, OUT0)
VOL
IOL = 2 mA
0.4
0.8
V
High-level Input Voltage
Low-level Input Voltage
High-level Input Current
VIH
VIL
2
V
V
VIH =2.4V,VCC
= 3.6V
VIH =VCC=3.6V
IIH
IIH
1
10
uA
uA
(PDN /SELX , OE)
(OSCIN)
Low-level Input
IIL
IIL
-1
uA
uA
Current( PDN /SELX , OE)
VIL=0,VCC=3.6V
VIL=0,VCC=3.6V
-10
(OSCIN)
Supply Current (Active)
DS1073-100
ICC
CL = 15 pF
25
50
mA
DS1073-80
(both outputs)
DS1073-66
DS1073-60
Standby Current
(power-down)
ICCQ
Power-Down
Mode
0.8
uA
17 of 18
DS1073
AC ELECTRICAL CHARACTERISTICS
(TA = -40°C to +85°C) (VCC = 2.7V – 3.6V)
PARAMETER
Output Frequency
Accuracy
SYMBOL CONDITION MIN TYP MAX UNITS NOTES
VCC = 3.15V,
fO
-0.5
0
+0.5
%
TA = 25LC
Over temp and
voltage
Combined Frequency
Variation
-2.5%
-0.5
2.5%
%
ꢃfO’
ꢃfO”
Long Term Stability
+0.5
50
%
MHz
1
2
External clock
Crystal
Maximum Input
Frequency
fOSCIN
25
MHz
kHz
ms
reference
Minimum Output
Frequency
fOUT
tPOR
29.3
3
+
Power-Up Time
0.1
1
4, 5
tSTAB
tSTAB
tSTAB
tPDN
0.1
0.1
1
1
1
1
ms
ms
ms
ms
5
5, 6
Enable OUT from PDN ↑
Enable OUT0 from PDN ↑
I/O Hi-Z from PDN ↓
tPDN
OUT0 Hi-Z from PDN ↓
Load Capacitance
(I/O, OUT0)
Output Duty Cycle
I/O
CL
15
pF
7
8
40
40
60
60
%
%
OUT0
Jitter
J
100
pS
NOTES:
1. Additive to ꢃfO’.
2. This is the maximum frequency which can be applied to OSCIN, or the maximum crystal frequency
that can be used. If a crystal is used, it must be operated in fundamental mode.
3. The values of M, N and the frequency of OSCIN (if used) must be chosen so that this spec is met.
4. This is the time from when VCC is applied until the output starts oscillating.
5. When the device is initially powered up or restored from the power-down mode, OE should be
asserted (high). Otherwise the start of the tstab interval will be delayed until OE goes high. OE can
subsequently be returned to a low level during the tstab interval to force out low after the tstab interval.
If the external mode is selected, tstab will be a function of the OSCIN period, i.e., external clock
frequency. See “Calculated Parameters” to determine the value of tstab in this case.
6. Although OE does not normally affect OUT0 operation, if OE is held low during power-up, the start
of the tstab period will be delayed until OE is asserted. If OE remains low, OUT0 will not start.
7. Operation with higher capacitive loads is possible but may impair output voltage swing and maximum
operation frequency.
8. Parameter given is a typical max.
18 of 18
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