SMM150
Preliminary Information
APPLICATIONS INFORMATION (CONTINUED)
Fault Latched by a Fault Condition:
The “Fault Latched by a Fault Condition”
programmable option is triggered only on the leading
edge of a Fault. That is, a latched fault can be cleared
while the Fault yet exists.
Fault Latched by Ready I/O Pin:
Fault Latched by Ready I/O pin functions on the
margin transitions from Off to Hi/Low/Nominal or from
Nominal to Hi/Low or Hi/Low to Nominal but not from
Hi/Low/Nominal to Off.
WRITE PROTECTION
Write protection for the SMM150 is located in a volatile
register where the power-on state is defaulted to write
protect. There are separate write protect modes for the
configuration registers and memory. In order to
remove write protection, the code 55
HEX
is written to
the write protection register.
+VIN - 2.7V to 5.5V
READY
MDN
MUP
Vdd
FAULT#
R3
20
U3
Vdd
1
2
D1
DIODE
J1
1
3
5
7
9
Gnd
SCL
Gnd3
SDA
Rsrv5
MR
+10V Rsrv8
+5V Rsrv10
2
4
6
8
10
1
28
8
6
4
2
7
SCL
SDA
WP
A0
A1
A2
GND
J2
1
2
25
24
C1
0.01uF
C2
0.1uF
C3
10uF
C8
0.1uF
21
11
5
7
8
11
9
C9
0.01uF
U2
+Vin
+Vin
Enable
+Vin
Gnd
Gnd
Other codes will enable write protection. For example,
writing 59
HEX
will allow writes to the configuration
register but not to the memory, while writing 35
HEX
will
allow writes to the memory but not to the configuration
registers. The SMM150 also features a Write Protect
pin (WP input) which, when asserted, prevents writing
to the configuration registers and EE memory. In
addition to these two forms of write protection there is
a configuration register lock bit which, once
programmed, does not allow the configuration
registers to be changed.
A2, A1, A0
The address bits A[2:0] can be hard wired High or Low
or may be left open (High-Z) to allow for a total of 21
distinct device addresses. When floating, the inputs
can tolerate the amount of leakage as described by
the specification I
AIT
. An external 100k pull-up or pull
down resistor is sufficient to set a High or Low logic
level.
DC-DC Converter
VOUT = 1.5V
+Vout
+Vout
+Vout
Sense
Trim
1
2
4
3
10
READY
VDD
Programming Supply
COMP2
12
14
C10
0.1uF
R4 2.5k
10
C4
0.02uF
C6
0.01uF
R5
1.37K 1%
R7
1.02K 1%
SMM150
VM
TRIM
20
I2C SMX3200 Connector
CAP_M
VDD_CAP
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
R6
3.83K 1%
R8
C7
0.01uF
25.5K 1%
3
9
13
15
16
17
18
22
26
27
23
C5
1uF
Figure 6 – Typical applications schematic which shows the SMM150 controlling a 3.3V in/1.5V out DC/DC
converter. Care should be taken to filter DC/DC converter noise from the SMM150 VDD supply pin. This is
accomplished with optional components R3, C1, C2, C3 and C10. This example, using a 1.25V VREF, also
shows the COMP1/2 pins monitoring the DC/DC converter VOUT set to an OV of 1.7V on COMP1 and a UV of
1.3V on COMP2, the voltage divider resistors are:
For OV, R5 = 1.37k, 1% R6 = 3.83k, 1%, For UV, R7= 1.02k, 1% R8 = 25.5k, 1%.
The jumper J2 can be used to supply the SMM150 VDD voltage from the SMX3200 programmer when the
device is programmed with board power off and the controlled supply unloaded.
5
6
MDN
MUP
FAULT#
COMP1
19
Summit Microelectronics, Inc
2075 2.6 05/13/05
11
SUMMIT [ SUMMIT MICROELECTRONICS, INC. ]
